I would say that the death of his first wife Arlene and the aftermaths of the Trinity Project affected Feynman greatly, as exuberant as he is usually.
Feynman's magnificent exuberance and puzzle solving enthusiasm was also illustrated during his last days, where his coworker Christopher Sykes remarked "Look at this man. He faces the abyss. He doesn't know whether he is going to live through this week. But he was consumed by it, and he worked on it all day long...."
http://www.youtube.com/watch?v=Fzg1CU8t9nw#t=1h11m46s
I would say that the death of his first wife Arlene and the aftermaths of the Trinity Project affected Feynman greatly, as exuberant as he is usually.
Feynman's magnificent exuberance and puzzle solving enthusiasm was also illustrated during his last days, where his coworker Christopher Sykes remarked "Look at this man. He faces the abyss. He doesn't know whether he is going to live through this week. But he was consumed by it, and he worked on it all day long...." http://www.youtube.com/watch?v=Fzg1CU8t9nw#t=1h11m46s
Feynman was the epitome of the "Doing things for the fun of it" philosophy. His last words to his artist friend Jirayr was "Don't worry about anything~! Go out and have a good time~!" http://www.youtube.com/watch?v=Fzg1CU8t9nw#t=1h32m10s http://www.youtube.com/watch?v=Fzg1CU8t9nw#t=1h32m10s