I have days where I feel like crap and I look at my body and I'm like, 'I haven't been able to work out as much. I can see my butt drooping a little bit.' And I'm just like, 'Oh well.'
As an actor you have to have a strong vivid imagination as you're working and when the camera's rolling, but there's certainly a part of you that is aware of real life, that you're making a movie.