pretty maniacal about microsoft, and only in my late 30s, with some encouragement from my wife melindaamelinda, did i start toy and talk with her about it. we knew we would do it by the time i was 60, but as we were doing the learning we decided to accelerate it and found a lot of ways to have high impact. >> rose: the principle mission call is all lives are equal. >> that's right, and a lot of that outside the united states has gone to save lives and have kids grow up to be healthy. >> rose: how did you decide that you would rather give your money to the gates foundation rather than create a foundation of your own and go out and find people to run it and do whatever you wanted to do. >> my first wife susie and i started the foundation over 50 years ago and we talked about it since we were in our 20s. i said to her, if i compound money at the rate i hope to compound money, there will be likely large sums later on, you're good at giving it away, i'm good at making it, so i'll make it and you give it away. she thought it was sort of half a cop-out, half logical. ( laughter ) so we did something,