I saw this award winning Russian animation short sometime back - Its called GAGARIN. After watching it,I felt it spoke of those who tried before their time and failed. Not sure how relevant it is to this post, but I try not end up like Gagarin.
Wish I had an answer for you and for myself :)
If you look at the crazy people who made it and sane people who got burnt out, you'd stop asking this question. The lesson I took away from this was that when you think you have recovered, with time you have grown wings (or whatever you need to accomplish what you started out for), make sure to clear up the history and restart as a curious kid.
PS: To me, Gagarin did not restart - was central idea of the animation.
http://www.youtube.com/watch?v=iA7RKwhrOT0