I'd prefer not to act in the film I'm directing. I think, though, as an actor, you do learn how to turn things on and off quickly and kind of compartmentalize. You learn to accommodate the camera and the other actors, to notice where the boom is and where you mark is, and be able to repeat something a few times.
Life is the movie you see through your own eyes. It makes little difference what's happening out there. It's how you take it that counts.