In theater, you've got to be aware of your whole body because it involves stamina. It involves two-and-a-half hours and a sustained release of energy, maybe for six months.
I think the thing about film is, as it gets proved by a lot of young filmmakers now, that the medium will just go on reinventing itself, and so you just hope to be a part of that and not a part of some kind of endless regurgitation or 'Here I am doing what you know I do' kind of thing.