I think it serves the purpose of the film if the premise is that you're unsure of me because you've only ever really seen me play villains.

Rowan Joffe is very specific. I mean, he wrote it as well and he has a very orderly writer's mind and the same applies to his directing.

Rowan Joffe was on top of everything. He knew exactly how he wanted everything to be, right down to the fact when I made those telephone calls, I didn't do it afterwards in a studio. I think that's how he operates. He likes it to be as real and as clear as possible.

In the film industry you never really know if all the various ingredients will come together - sometimes they do, and sometimes they don't. As an actor, you don't have much control over those things. It's a director's medium in that sense. All you can really do is minimise the risks of being involved in something that might not work and look for something that also suits you.

Because I had children relatively late - in my 40s rather than in my 20s - it wasn't anything I ever knew that I would do. It kind of happened to me: I met the right woman and we had children. It was a revelation because it suddenly makes me realize "Oh, I get it. Now I know what to do with the rest of my life."

I loved making The Imitation Game and it's really gratifying to hear the audience's response to the character that I play. It was just a little thing that I did because I really liked the film and I liked Benedict [Cumberbatch] and I loved Morten's [director Morten Tyldum] previous film, Headhunters. For me, it was something I did thinking, "Wow, this is a lovely quality piece of work."

The idea of transformation - playing something I'm not - is the bit I enjoy most about acting.