You're working so hard and so many hours, you simply don't get to visit with everybody when you're gone for five months. That's part of the trade in we make with this career. You don't get to maintain the intimacy you would like to.One of the big things I was doing was working on reestablishing that.

I was eating with the help of a nutritionist so I was definitely putting in the appropriate calories and vitamins and minerals into my body; however, it was still so little that if I had the tiniest piece of sugar, my brain would go crazy. If I had some alcohol during the run of that play, my brain would go crazy.

I'm a trained actor and I can always tone it down, I can always simplify the work I've done. But if I'm asked to bring the nuanced and complicated work, I'll have it in my pocket, and all that information helps.

You get a role like this in a big action movie [like Jack Reacher] and you can go one of two ways: you can paint in broad strokes, which happens a lot in action films, or you can get very detailed.

I had heard that Tom [Cruise] was the same way, that he is incredibly dedicated. I was very excited to meet him and I was, honest to God, weirdly surprised that the guy makes me look lazy. I think he does think I'm a hard worker, but he makes me look like I'm doing nothing. The guy is at the gym before anybody in the morning.

The role I played [in theatre] was originated by Ian McKellen in 1979 and he came. I didn't know he was there and I walked out at the end of the play, which is a very intense play - my character is required to do some really horrible things - and the director was waiting backstage and he goes, "Obviously I didn't want to tell you guys, but Ian was here today" and we, of course, freaked out.Ian McKellen said some really beautiful, kind things, one of which was, "It's so much harder to watch than it is to do."

I read as many books about the psychology of a psychopath as I could and I researched what exactly happens to soldiers.