I start a boxing movie and that's kind of something I've been able to get to the gym for. It's great anytime you can parallel a skill that your character has. I just think it makes it even more rewarding.

Four is a powerful figure in literature and physical form

I'm the type of actor that believes the director has to be in charge. I've been on sets where the actor's ego was the most important thing, and with a director that messes it up. But I don't like a dictator, I want it to be collaborative - the best idea wins. If I feel respected, and I'm going to give that back. If a director wants to try something, cool, I'll give it back. I also feel like they cast me for a reason, so I'm going to make my mark on it... let me do my thing.

I was in good shape from Divergent. Damien Chazelle, the director of Whiplash told me, 'Stop Working Out! Don't go outside!' He wanted me pale and doughy. This is the first movie where I shut myself off from the world. It was, by far, the hardest thing I've ever done.

I've played drums in bands since I was 16.

I was not a band geek, per say. But me and my two older sisters played instruments, so I would come home and my sister Dana would be playing the clarinet or playing the piano, and I would play the saxophone, my other sister would be singing, my mom would be singing. I was not afraid to be musical. That was not something that I thought was uncool.

I got into acting my junior year of high school. We got a new hot drama teacher and I was like 'Alright, I'll try drama.'