You can act truthfully or you can lie. You can reveal things about yourself or you can hide. Therefore, the audience recognizes something about themselves or they don't -- You hope they don't leave the theatre thinking that was nice...now where's the cab?'
I was coming from a very cerebral, dark, difficult, layered play by Christopher Hampton and doing an action movie in Hollywood (Die Hard) with explosions, and I was holding a gun.
I'm very aware that when one is acting in the theater, you do become kind of animal about it. And you're reliant on instincts rather than tact a lot of the time.
I've learned, having been on a lot of sets, the good news is that by definition you are surrounded by experts. They get fired if they're not - unlike in the theatre!