To be physically fit is just a small aspect. You can be a beautiful physical specimen, but you're empty as far as what it takes to be a person, and that shows up real fast.
“The one thing I learned the most about acting is it takes a tremendous amount of courage to go there and stand still. It takes courage and guts to step out of your mind frame and depict something.”
“With any part you play, there is a certain amount of yourself in it. There has to be, otherwise it's just not acting. It's lying.”