and i can handle it. >> reporter: dr. azari and his team began by first amputating jonathan's left hand, preserving his nerves and blood vessels for the eventual transplant. but dr. azari also told him to get stronger and healthier. he was also gauging something else. what did you size up about his mental toughness? >> his mental toughness was what actually got me to fall in love with his personality. he is an eternal optimist like i've never seen before. >> reporter: but the eternal optimist faced a grim reality, that his right leg could not be saved. >> that was an extraordinarily painful moment. she was crying with me. it was -- it was a real get it out cry. the admission that we had lost that battle was really tough for both of us. >> reporter: he may have been missing a leg, a hand, all of his fingers and toes -- but even in defeat -- >> come on, baby, push it! >> reporter: jonathan kept fighting in order to qualify for that hand transplant. >> you're literally getting better. >> reporter: the first milestone? learning to