I only had a three-week break from the beginning of Bent, so I went from one thing to the next. I got back [from shooting Jack Reacher] and there was a sense of, "Oh my God, what do I do now?" I don't have personal trainers around me all the time, I'm not on a meal plan, which I had been on for almost a year straight. There was a lot of sleeping.

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."

When I look at myself in the mirror, I don't see the bad guy.

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

My character is called The Hunter. He's the main antagonist in the movie. In a nutshell, he's a slightly deranged natural born killer who's weirdly determined to succeed at his job, whatever his employment is. He's a mercenary and there's a high body count for him in this film [Never Go Back].

Psychopaths don't have that charming skill set. They definitely manipulate, but they do it through focused, unskilled means. They're more obsessive.

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.