There's no staying where you were. If you're not doing anything, your skills and point of view are atrophying.
My craziest on-set story comes from during the Goonies, when I came up to Spielberg and said that I wanted to climb the walls of the tunnels and that it represented my mother's womb, for some odd reason. I was reading Stanislawski at the time and Spielberg's response was "Why don't you just act. "