I had just come off of doing a play in Los Angeles which actually got me the role. It was called Bent and it was at the Mark Taper Forum. I was playing a homosexual in 1930 to 1934 Berlin who is eventually put into a concentration camp for the second half of the play. I had lost about 38 pounds for that.

When I did Casual, I just let myself put on weight because he's a schoolteacher. He's not meant to be muscle-y.

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.

Sociopaths are more complicated psychopaths; the difference between a sociopath and a psychopath is a sociopath is incredibly charming. There are a lot of sociopaths that are CEOs. They don't necessarily kill people but they're able to walk into a big social function and make everybody think they're the kindest, coolest, smartest, most interesting person in the room.

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'm obsessive about my job and I want it to be as great as it can possibly be, especially right now in these early parts of my career.

I'm not a method actor but it certainly does help to have that kind of dedication. I treated my preparation like I was in the military. I didn't go out ever. I went out for drinks probably twice in five months. I lived very monastically.