Proud but not satisfied

Check out this article by John Carlin on Rafa Nadal on him nurturing his doubt being such a big part of his success.  FT Magazine - Rafa Nadal

excerpt - But my way is this: when you believe that things are going to go your way just because you are who you are and because you are very good, that's when you start to get careless, when you stop working hard, when you stop fighting for every point.  You lose your intensity and while things may go well with you for a while, because you've built up a positive momentum, it won't last.  You drop your guard when you stop having doubts about yourself.  I've always had doubts.