If I'm not afraid when I'm reading a script, that means I know I've done it before. If I read something and think, Wow, I can't play this part, then I want to play it more.
I learned my business in the theater and in television, particularly working with the actors. You can learn much more in the theater than directing a movie, because then you have no time when you are shooting a movie to really work with the actors. You have to learn this craft somewhere else.