It's that athlete's obsessiveness - the need to prove yourself and work harder than anybody else. I think it's what helped me do well in the theater. ↗
It's not easy to strap yourself down to a desk and bash on a keyboard when you know you can direct lots of films, because directing films is fun and interactive and gregarious. Writing isn't. ↗
I guess there is nothing that will get your mind off everything like golf. I have never been depressed enough to take up the game, but they say you get so sore at yourself you forget to hate your enemies. ↗