>> announcer: the choices we all have to make. what we wrestle inside our head. will we choose love or lust? to tell the truth or to lie? when what we choose can to the dream or a nightmare. tonight, the ultimate test of love. a young married couple risks everything by putting their love on the line. we joined them on the journey of a lifetime. but, will the trip seal their love or break it? >> we talked about giving up. >> reporter: for the first time ever, we go inside their minds to find out. >> this is on depressing. >> reporter: the results will shock them both.

plus, paralyzed by love. the extraordinary story of a husband whose body literally shuts down at the thought of his wife. a romantic photo, a touch and this happens. it's scary. and, bringing love back. this man was hit by a truck and forgot everything including his love for his wife >> i was going to have to start saying good buoy to who he was. >> reporter: but she would not give up. can he learn to love her again in. good evening, i'm cynthia mcfadden. and welcome to "nightline" prime. and our new series, secrets of the mind. we're going to take you on a journey to challenge everything you thought you knew about love. how we fall in love and how love endures in toughest of circumstances. join us as we show you what love

is. >> reporter: how do you know if you're really love in someone? mike clear thought he was madly in love when he publicly proposed to his girlfriend at the airport. and alanna boyle thought he was madly in love when she accepted. both felt in love at their 2008 wedding. so, as they started their life together, mike was really alarmond to hear that 50% of marriages end in divorce. >> the thing that really kind of struck me, everyone who goes to the altar are in it for the long haul. but yet 50% fail.

how do we stay together for life? >> reporter: to find out, mike clear had a radical idea. they would put their young love to an extreme test. >> we're going to quit our jobs. >> reporter: traverse the longest road in the world. the pan american highway. in this motorcycle and side car. howing to mimic the stresses of a lifetime. in this single road trip. >> all of the way down the pan american highway, through 16 countries. >> alaska. >> san miguel. 20,000 miles over 8 1/2 months. >> it was really scary. >> reporter: so you're as crazy as he is? >> pretty much zbr but first, they would turn to cutting-edge silence to prove whether or not he and alanna were clearly in love. they had their brain scanned under the supervision of

world-remoaned an tlop logist helen fisher. dr. fisher said that there are three types of love that you can see in the brain. sexual love, romantic love and attachment love. dr. fisher says people come in saying that they're in love but their brains show otherwise. >> in this envelope are all of the results. >> we're hoping it's going to be positive. we're we're only going to open up the envelope at the end of the world. >> reporter: would all of that time together increase their love or pull them apart? they would take a second brain scan afterwards to find out. the start of the trip began with intense emotion. alanna was scared to leave her secure world behind. plus, he failed her motorcycle

driving test. >> not my lucky day. >> i thought she was more upset of driving the 28,000 all alone. >> reporter: their trip began in anchorage, alaska. along the way, they planned on interviewing other couples, asking them the same question. >> what is the secoret of love? >> keep all of your ups and downs. >> i came in, i don't think i could do this. i don't think i can listen to people telling them about their love stories. >> reporter: some people are going to be listening to the two of you and they're going to say, love is mysterious. the attempt to study it grinds it down into something else. >> we kind of go, if we stop pulling it out and which brain

systems firing, will we love each other? >> reporter: but they soldiered on and headed south in good spirits. >> today has been a good success. >> reporter: but, it wouldn't be long before the trip started taking its toll. >> we have been been driving all day, i just want a shower. i'm tired and grumpy. >> we're covered in mud. and i want to get out of this country, now, please. >> reporter: next, they headed to utah, where the trip almost came to an abrupt halt. how did the bike get into the ditch? >> well, the driver was lost in discussion about having a baby. >> i was talking about having a baby over the microphone and he lost concentration in a moment of pure terror.

>> reporter: through night fall. >> it's pretty brutal. >> reporter: exhaustion. >> i'm literally shake sflg i'm really tired. >> reporter: extreme cold. extreme heat. >> sweating like -- >> i like to think it iz as the alanna, you're so hot moment. >> time management. she needs to be better without being a complete -- >> reporter: any fight about directions. >> she lost the gps in las vegas. >> we're in vegas, baby. >> reporter: but in vegas, the king gave them some words of wisdom. >> thank you very much. >> reporter: weeks later, it was gat mall ya. >> men are circling like sharks. >> reporter: where the rain would just not stop.

rain is on the way. >> oh, my gosh. >> it's rain something hard. we would be driving through lightning storms and we couldn't sigh anything. and anything was dry because it was so wet. it was really unromantic. >> reporter: there were great high and last night was really, really romantic. we had such a fun time. >> look at his little feet. >> reporter: and miserable lows. >> what could possibly go wrong? >> the marriage is on the rocks. >> we have been been talking about giving up. >> reporter: what affect was this having on their love? on this 29,000-mile relationship crucible. >> gone the distance. >> and we're still together. >> reporter: was drawing to a close. they took with them 120 answers

to the question, what is the secret of lasting love? >> love is allowing somebody to be themselves. >> find the imperfections in each other and love them. >> reporter: and what they hope what was a better understanding of the person they just decided to spend the rest of their lives with, you have to decide to be in it. >> hollywood's idea of romance, where mr. right walks into the room, suddenly you feel like you're complete. it's never going to be like that. you have to decide, okay, well, i thought i was going to maryry somebody dark and handsome. you're so handsome. >> reporter: finally the moment of truth. had they been in love when the trip started and the envelope, please. >> we predict a lasting relationship. we think you guys are made for one another.

>> reporter: they were in deep romantic love before this thing started. both their brains lit up like christmas trees in the romantic love center. >> are you ready? >> i think so. >> reporter: but, what about now? the second test would follow, what would their brains tell us about the effect of the intense road test. >> there was nothing here at the trip. >> reporter: they put their love to test, but, did they fail? find out when we come back. this droid has evolved to do even more. now it integrates your work e-mail, so you can be hooked up to everything you need to do. now it does 1 ghz speed on a more intuitive keyboard. turning you into an instrument of efficiency.

introducing the new droid 2 by motorola. part of the next generation of does. [sfx: sighing] ♪ if you're taking an antidepressant and still feel depressed, one option your doctor may consider is adding abilify. abilify treats depression in adults when added to an antidepressant. some people had symptom improvement in as early as one to two weeks after adding abilify. now with the abilify (me+) program, your first two weeks of abilify can be free.

abilify is not for everyone. call your doctor if your depression worsens or you have unusual changes in behavior, or thoughts of suicide. antidepressants can increase these in children, teens and young adults. elderly dementia patients taking abilify have an increased risk of death or stroke. call your doctor if you have high fever, stiff muscles and confusion to address a possible life-threatening condition. or if you have uncontrollable muscle movements, as these could become permanent. high blood sugar has been reported with abilify and medicines like it. in some cases, extreme high blood sugar can lead to coma or death. other risks include decreases in white blood cells, which can be serious, dizziness upon standing, seizures, trouble swallowing, and impaired judgment or motor skills. adding abilify has made a difference for me. [ male announcer ] visit abilifyoffer.com for your free trial offer. and ask your doctor about the risks and benefits of adding abilify. hi. we're ready to switch our car insurance to progressive. today just seemed like a great day to save. oh, it's not just today.

with our free loyalty program, you earn great stuff like accident forgiveness and bigger discounts just by staying with us. oh! ooh! so, what you're saying is, it gets even better with age. oh! tell me we're still talking about insurance. rewarding loyalty. now, that's progressive. call or click today. fancy feast created a wayhat to celebrate any moment. fancy feast appetizers. simple high quality ingredients like wild alaskan salmon, white meat chicken, or seabass and shrimp in a delicate broth, prepared without by-products or fillers. fancy feast appetizers. celebrate the moment. sfx: (kids laughing and talking)

♪ >> reporter: mike and alanna clear wanted to find out if they were dessined to stay together for life. you remember, they set off on a 20,000-mile road trip.

>> the open road. >> reporter: even had their brains scanned before they started. proving they were, indeed, in love. but, now it's time to see what their brains say happened after 8 1/2 months on a motorcycle together. the results of that second test shocked them both. >> we're going to look at mike before and after. the trip. as the activity has shifted into attachment system areas. we have gone from euphoria to attachment. >> my passion is very much like burned out. none of the same activity that you saw in the first one. >> now, we're going to look at alanna. alanna is still euphoric. >> reporter: it's disappointment moment. mike, has he lost his passion for her? >> the first one was very similar. the second one, we were totally

different. that's where i'm like, have we opened up the pan doer ya's box. >> they came off the trail, they were both exhausted. >> of course, we want all three brain systems to be triggered all the time throughout the entire relationship. don't forget, that romantic love comes and goes in a long-term relationship. >> reporter: it's been six months since that trip and that dede moralizing second scan. they do feel romantic towards one another, they say, but that second scan is overshadows their marriage. this time, alanna's take nothing chances. >> your brain is going to be on fire again. >> reporter: they danced to their wedding song.

before they go into the scanner. >> are you nervous? all right final words? >> i don't feel nervous. i just hope -- hope something's happening in there. >> reporter: alanna goes first. she looks at pictures of mike as her brain is being analyzed. >> i'm feeling nervous. it's such a horrible feeling just going in there. >> reporter: it's mike's turn. not easy considering that mike is klaus frclaustrophic. one last kiss and in he goes. >> just close your eyes and relax.

>> did you feel love for me. >> yeah, yeah, enormously. >> reporter: now begins the long result for the test. mike and alanna goes back to london. dr. fisher calls them. >> i can't wait to tell you the results. i'm delighted to tell you, that in your brain, mike, we found activity in that brain region associated with intense romantic love. so, you're both in love and you're bothly deeply attached to each other inspect. >> okay, good. she's craig over here. you can't see the tears. >> that's so sweet. it's so sweet. >> i was worried about you. the last results made me rally sad. so, this is lovely. >> timely, my brain is behaving

itself. >> here's mike's brain. test one. test two. and a very happy test three. >> reporter: what is the secret to lasting love. >> one guy gave us a piece of advice, you got to marry the right person. >> reporter: have you? >> of course, the response has to be, have you married the right person? >> yes, absolutely. when we come back, just a kiss, just a touch, even just a thought, do this to matt. we meet the man who's literally paralyzed by love. we speak value. and people like what we're saying. about how fusion is projected to hold its resale value better than camry. and has better quality than accord. as a matter of fact, people like what we're saying so much,

ford fusion is now the 2010 motor trend car of the year. the fusion, from ford. get in . . . and drive one. [ female announcer ] yoplait's real fruit and the goodness of dairy gives you a little slice of happy. and happiness comes in 25 delicious flavors. yoplait. it is so good.

think you've mastered all there is to angus-ology? think again. feast your eyes on this. mcdonald's new angus snack wraps. it's what you love about the angus third pounders. 100% juicy angus beef, hickory-smoked bacon, and crisp red onions. mmm! in a wrap. so, what about that free hand? oh. so now the student becomes the teacher. you're graduating angus cum laude. the simple joy of angus. ba da ba ba ba!

we all think we know everything about love. except on days that we don't anything about it. ♪ ♪ your love is my drug >> reporter: 85 per suspect of us think we're in love any point in time. hollywood sure doesn't think so. when we don't feel it. sometimes even we do, there's always the movies to remind us. from love story. >> love means never having to say i'm sorry.

>> reporter: to noting hill and in crimes and misdemeanors. there's love. >> my ex-husband and i fell in love at first sight. maybe i should have taken a second look. >> reporter: and sometimes with regret. men have between 6 to 8 partners in their lifetime. women have four. are they in love with all of them? so, what is love? find out more when "secrets [ banker ] when ashley's violin teacher told her parents she was gifted, they were thrilled. she's a natural vibrato. oh. we started saving for this music camp in vermont. so i told them about some of the wells fargo online savings tools like my savings plan, which helps them set up and monitor a savings goal.

until we found out that maybe her teacher uses certain terms a little bit loosely. rebecca is clearly very gifted. [ banker ] we decided to roll that money into ashley's college account. turns out there's seven gifted kids in ashley's class of nine. [ male announcer ] wells fargo. with you when it's time to save. ♪

>> reporter: this is what it looks like to be in love. it's a struggle to keep your eyes open. >> his eyes look heavy. >> yes, he's having a tough time. >> reporter: it's your neck giving in to gravity. >> matt, are you still with us? >> reporter: and then, you disappear inside. at least this is what being in love looks like from matt frerging. >> is he okay? >> reporter: being in love with

this woman, trish. matt is trapped. matt, my asked you to move your finger, can you move your finger? no. trapped by a disease narcolepsy with cataplexy. matt, sitting, he's not any pain. but he's fully awake. but a trigger has left him paralyzed and matt's trigger is love. love for trish. love for his stepchildren and their children. that basic, positive human emotion, becomes a prison for him. if matt's eyes are open. >> he's opening them up. >> reporter: things that most of us long for, having our grandchildren and children, all of things that most of us live for, are things that you have to avoid. >> yes. i have to limit those things very quickly. >> the brain is behaving as if

it's asleep while matt is awake. >> reporter: she has seen many similar cases similar to matt. matt's particularly extreme case. >> specifically the brain is behaving as it would in this state of dreaming. that switch gets turned on. that inhikts the muscles at night so that you can't get up and start running in your sleep, turns on during wakefulness. and suddenly, you're paralyzed. >> reporter: strong emotions are tied to memories of their past lives and anniversaries are especially difficult. >> wedding photos. that was a good day. and i think that's about all i can really say about it. >> reporter: we met matt and trish the weekend before their 13th anniversary.

>> you had a mullet. >> reporter: the everyday e monthsal moments that most people cherish are landmines to matt. the walls of their oregon home are nearly bare. only a few family pictures remain. but mostly, out of sight. or stashd away in albums. if not, this happens. >> you kyou move? getting tough. >> reporter: you have an emotional beacon, once it gets full, it overflows. >> lot of effort goes in to keep that beacon low. when things get a little bit more full, there's someplace for it to go. >> reporter: without sloppy over it and you going down? >> right. >> reporter: matt was completely healthy four years ago, when at 35, the disease suddenly attacked. >> when you look at most american marriages, most women complain that the men aren't

emotional available. well, you got it in spades. >> i happen to really love him. >> reporter: at home, they spend time together by spending it apart. >> they call this parallel play. matt does his thing and i do my thing. you know, we interabout every once in a while. on how his feelings permit. >> reporter: for their anniversary, they're attempting to go out on a date. but leading up to the date, we witness how the simplest things become threatening to matt. like the new dog that trish got. >> so mom would have someone to play with. yeah. good girl. >> reporter: how was the puppy a substitute for matt? >> i think i'm a touchy person. >> i'm the person who ignores her far more than i like.

she is adorable. but, it's just not something that i kelcan really focus on. >> why just the positive one and positive emotions trigger chemical release in a way that activates this process. exactly how and why it all works, we're still in our infancy in understanding it. >> reporter: what helps matt are dark thoughts. trish pushed him to go to a family gathering recently where he had a massive attack. the only thing that brought him out of it, was -- >> thinking about what it would be like to be disavowed. it's not okay to put him through that. >> i am probably a grumpier person than i have been in the past. trish can speak to that better than i can. >> reporter: true?

>> yeah. yeah. >> reporter: in old photos matt was a grinner. but the disease has affected his muscles and mood, it has made smiling rare. the initial cataplexy was a lot worse. the past two years it's been managed by a potent cocktail. and comes in handy when they take a walk in a rose garden near their home. >> a sort of place where people go to relax and appreciate each other's company. >> reporter: minutes after arriving matt feels an attack coming on and find a bench. the attack takes hold. >> when matt has an attack out in public, i try to move away. but, still keep an eye on him. >> reporter: after five minutes with people hardly noticing,

matt fights off the attack and returns. >> i'm all right. >> reporter: the park brings back memories of what their lives were like. >> we were pretty affectionate people. we would hold hands. >> i'm going to stop looking at you, because it's not -- it's not easy. >> reporter: if matt can't even look at trish, what what happens when they kiss? do you sleep in the same bed? when we return. ♪ [ dog panting ] [ dog sniffs ] [ cat meows ] [ cat meows ] ♪ [ male announcer ] cats everywhere are using fresh step with carbon because it doesn't just mask odors, it eliminates them. so don't be surprised if your cat needs help finding her litter box. fresh step, the only clay litter with carbon. it's paw-activated, to eliminate odors.

so it's almost like not having a litter box. although more maneuverable than its burger predecessor, its payload is still substantial. angus beef bundled with fresh tomato and crinkle-cut pickles in a sleek, snack-sized wrap. so it is imperative to keep the nose of the snack wrap elevated to ens-- pull up! pull up! to ensure the contents do not shift in transit. angus axiom number 81. please remain seated for the duration of the feast. mcdonald's new angus snack wraps. the simple joy of angus.

♪ the simple joy of angus. there's oil out there we've got to capture. my job is to hunt it down. i'm fred lemond, and i'm in charge of bp's efforts to remove oil from these waters. you may have heard that oil is no longer flowing into the gulf, but our spotter planes and helicopters will keep searching. we've still got thousands of vessels ready to clean up any oil we find. we've skimmed over 35 million gallons of oil/water mixture. i grew up on the gulf coast and i love these waters. we'll be here as long as it takes to clean up the gulf. [ panting ]oh!! ♪ max!!! no!! [ female announcer ] windex multi-surface lets you keep up with messes right when they happen. [ sprays ] so you can put that windex shine -- on just about anything. [ sprays ] [ jeff ] [ chuckles ] did you see that? wayne? wayne!!?!? [ laughs ] got ya!! [ female announcer ] get windex multi-surface and keep up.

sc johnson, a family company.

>> reporter: matt frerking has a rare disease that leaves him paralyzed, literally. how do you have a marriage, how do you have a love affair with one another and stop yourself from feeling it? >> it's tough. i miss touching him. >> reporter: can you kiss each other, or does he just go bingo? >> there are pecks. i miss making out. >> making out is hard to do. >> yeah. >> reporter: do you sleep in the same bed? >> yeah. yeah. he can have an attack while

we're -- >> reporter: while he's lying down? >> that's the one time of the day when i get to wrap my hands around her. >> it's easier for mat tot have sex because the other is just too intimate. >> reporter: it's their anniversary morning and matt is already worried that he won't make it through >> it's important to be able to express to my wife how i feel about her. >> reporter: but first, he heads to work. there are two things that he has no problem doing. one, surprisingly is driving. it helps him focus and stay awake. >> as long as i carefully avoid emotional topics the risk of having an unprovoked, unexpected attack it's nil. >> reporter: the second thing is work. the deep irony in all of this is matt frerking is a

neuroscientist. he runs his own lab at the oregon health and science university. he ehas no pictures on the wall and the staff knows what to expect. at work, matt gets a call from trish. >> hey, hon. happy anniversary. >> reporter: she just received the flowers that matt sent her. >> she got the flowers. >> reporter: meanwhile at home, trish is prepping for tonight's date. >> trish, after all of these years, you still make me swoon. >> reporter: when he returns from work and she greets matt with a hug and a kiss -- >> happy anniversary. >> reporter: -- almost immediately he feels an attack coming on. and his voice trails off.

trish knows that she needs to remove herself from matt to recover. >> i'm going to head up stairs to give him some time. the episode has take hold and their anniversary dinner is only hours away. if you had known 13 years ago that this -- that you were going to have the disease, would you have still married her? >> no i, i don't think i would have. i think this would have been a devastating place for her and the kids. having said that, we are married. and, i love trish very dearly. very beautiful wife. >> reporter: matt breaks free of the cataplexy. but needs to lie down. on the way upstairs, he apologizes for trish for having an attack. >> oh, stop it. you're fine. i feel bad that he feels bad like he's putting us through

this bad thing. >> reporter: now, right now, you want to hug him. >> i do. >> reporter: and you want to comfort him and you can't even do the both simple thing. >> that's good for him. >> reporter: eventually matt and trish make it to their anniversary date. >> thank you. >> thank you very much. >> lucky 13. >> reporter: you must have wondered, trish, whether the best thing for him is to stay with him or to release him? >> i think we both agreed that's not the best thing. he still wants me in his life and i still want him in miss mine. once in a while we can do something nice. >> it was a good anniversary. >> not over yet, babe. >> reporter: so what have you learned about love in the last four years? >> love endures a lot. i love my wife.

and, no disease gets in the way of that. >> i think it helps a lot to be with the right person. the fact that it's hard for him is hard for me. i want to finish life with this guy. so, and i feel really thankful that he wants to continue on through life with me. >> reporter: despite being able to -- not being able to move when he's feeling love for you, i think we're in -- do we think we're there? matt? the talk of love. i mean the talk of love and once more, matt becomes paralyzed by love. a love he refuses to give up. >> announcer: when we come back, a romantic different, but only she will recall it later.

we investigate love without memories. when the stage is set. and the cast has been gathered. when the curtain rises. and the spotlight is yours. having a strong signal at your back... is like having invisible power everywhere. because in that moment... you're not there to take up space. you're there to fill the room. rule the air. verizon. right now, buy a blackberry smartphone and get a second one free. like the bold. only at verizon.

we'll see about that. glade lasting impressions. two complementary fragrances alternate to keep things... fresh day after day. and not just for 30 days. um... okay. our longest-lasting plugins ir freshener lasts for 60., well, that lasted longer than i thought. i knew it would. get freshness that won't fade away for 60 days. with plugins lasting impressions. and yes, it's glade. s.c. johnson. a family company. [ beep ] ♪ [ beep ] [ beep ] ♪ [ beep ] [ male announcer ] find an italian masterpiece in your grocer's freezer. new from buitoni. shrimp and lobster ravioli with garlic butter sauce. simple ingredients, artfully prepared. buitoni. create an italian masterpiece. discover more buitoni masterpieces in the freezer section.

di♪cover more buitoni masterpieces ♪ there's a land that i see, where the children are free. ♪ ♪ come with me, take my hand, and we'll live... ♪ ♪ ...in a land where the river runs free... ♪ ♪ ...in a land to a shining sea...♪ ♪ and you and me are free to be you and me... ♪ ♪

>> reporter: imagine that the person you love can't remember who you are. imagine every memory you shared wiped out. imagine the present moment is all there is. this is ana gaines' world. anna would have told you that

she's another young woman, very much in love. she was 25. as was her husband, derrick. they had been married for just over a year. >> not many periods in times, that things weren't going well. we were feeling so good about where we were in life. >> reporter: you were happy? >> we were very happy. >> reporter: they had met in college. where both were star students. >> look at these pictures from graduation. these are my absolute favorite pictures of us. >> fun-loving, athletic guy. >> reporter: both wanted children. >> definitely fell in love with you. >> reporter: three months after getting engaged, they married. they settled in her hometown of pittsburgh. and began creating the memories that last a lifetime. the memories that bind lovers together. but, his memories would seas on

that summer day. >> i remember that morning, he went to work in this cream-colored suit. nice blue shirt underneath. this beautiful tie. he looked so handsome. >> reporter: by that evening, everything changed and her vow to stay with him in sickness and in health would take center stage. the call from a friend came as a shock. >> she said i'm just telling you that you have to get to the hospital. >> reporter: a tire on 18-wheeler dislodged and piled through his wind shield, striking him in the chest and the face. leaving him unconscious and careening into another vehicle head-on. >> when i got to the hospital into the emergency room area, they just took me through the door and he was right there. on the gurney. he was -- it was terrible. he was all blooded.

he had all of these injuries to his face. had tubes out of everywhere. i didn't know what to say. i just told him that i was there. i think they were trying to figure out how to just save him, right? i remember looking up at the nurses and the doctors there, and i just said, please, do everything you can for him, because he's such a special man. >> reporter: as her beloved husband's life hang in the balance, she remain by his side. >> i sat by his bedside in the icu and read to him. >> reporter: when he did wake up a month later, she was devastated. when he opened his eyes, his stair was blank. >> you start thinking, that can't be permanent. he's still there. >> reporter: he lost his memory.

he had no idea who she was. he didn't even know who he was. it must have been terrifying? >> my wife was a question mark. i had a lot of questions. >> reporter: you didn't know your own name? >> no. x i didn't know my name. >> reporter: derek would have to learn everything all over again. if he could. >> he didn't know how to use simple objects. if somebody handed him a brush, he didn't know it was for his hair. she was overwhelmed. he looked at her as stranger. >> being back in house together was so unsettling to him. he felt trapped. he was confused. he was angry. and there wasn't anything about it as i hoped. >> reporter: was she supposed to stay?

and if so, how? >> he doesn't remember growing up, he doesn't remember college. he doesn't remember anything about our years together. he doesn't really remember the big milestones since his accident. >> i have memories of my own. from eem that i trust. but none come from my head. >> reporter: helen fisher one of the world's experts on love. what happens when one of the partners has no memory. i mean, can't remember the first date, the first kiss the first year of marriage, doesn't even remember the name of his wife. >> terribly traumatic for the person who loves that person. when there's a real barrier to a romantic relationship the person who's madly in love, just loves the person harder. that dopamine system in the brain becomes more active and you love them more.

>> reporter: isn't that the same area that awakes up. >> yes. >> reporter: love is like cocaine? >> love is very much like cocaine, but it lasts a lot longer. >> when he first came home, i probably realized, that i was going to have to start saying good-bye to who he was and start working with who he is now. and it took me a long time. because, if somebody's sitting right in front of you and they look like the person you're in love, and they don't have any context of who you are, you can't really just good-bye to who they were. you know. >> reporter: she said that she decided to stay. and to make life as normal as possible. >> i believed that god had a bigger purpose. >> hi, dr., nice to see you.

>> reporter: as planned, she decided she would go to medical school and because of derek, she would specialize in rehabilitation medicine. although the old derek was gone the old desires remain. she still wanted children? but, was it fair to him? should he be a father? tell me about the conversation. because you must have talked about whether -- were you in favor, derek, initially d you think it was a good idea? were you worried? >> i'm not sure how i was initially. >> yeah. >> i don't remember. >> it was still a time in our life, where i was really making the decisions. i was talking with derek. because in the moment, he could have a conversation with me. but, he wasn't remembering conversation to conversation.

so, i talked to him about it for probably 30 times. >> reporter: it was a bold decision, though. >> agreed. >> reporter: justin gaines was born in 2003. >> i love that decision that we made together. i wouldn't trade it for anything. but now, i couldn't if i wanted to. >> reporter: you made it two more times, too. mariah is four and sean is number two. they make a pretty scene, playing ball together at home. even the children realize that daddy won't remember any of it. nevertheless, having the children has helped. >> i didn't expect having kids to be quite so miraculous for him. >> all right, mariah. >> and it wasn't right away. but little by little, he had something in his life that made him want to be better. >> good job.

>> reporter: i'm going to talk to you about the woman who's holding your hand here. there are a lot of people who are going to hear your story and put themselves in your wife's position and say, i don't think i could have done it. i don't think i could have stayed. >> they can, if they want to. bad enough, they can. you have to give up a lot. she had to give up a lot. >> reporter: she had a choice to make. she chose you. >> right, and i'm so glad she did. she's the best thing that ever happened to me. she always has been and always will be. i'll be with her -- i'll be by her side for as long as i can. >> reporter: once a week they try to make time for date night. hoping to experience the love they once knew.

did you go through the process, derek, of falling back in love with her? >> yes, very slowly. i had to learn who she was. i had to learn who i was. >> reporter: you have an unique experience in a way, you had your husband fall in love with you twice in. >> i would say so. >> reporter: over the last 13 years, they have built a life together and a new kind of love has blossomed. how or within it happened, neither of them know. only that it did. >> i love you. only that it did. >> i love you. >>[ children shouting ] come on, kiddo, let's go. [ laughs ] hold on a second...

come on up here where your brothers sit. [ birds chirping ] wow! did i ever tell you what it was like growing up with four sisters? that sounds fun. yeah...fun for them! [ male announcer ] chevy traverse. a consumers digest best buy. with a 100,000 mile powertrain warranty. it seats eight comfortably -- not that it always has to. it seats eight comfortably -- so we take time to sit down for lunch at olive garden and we enjoy catching up announcer: it's the unlimited soup, salad, and breadsticks lunch. only at olive garden. featuring four homemade soups. enjoy all you want for just $6.95.

next week, we ask, can you see evil in the brain? are some of us programmed to kill? to find out, martin bashir visited death row and went face to face with a confessed serial killer. >> what if i called you something that i didn't like, would you think about killing me? >> get your head down on the concrete, so be it.

>> but what happens when my head goes down the concrete? >> what do you think happens? it cracks like a coconut. >> reporter: and then what happens? >> you die. >> evil on the mind is next week. i'm cynthia mcfadden. thank you for joining us. for now, from all of