In the movie, you have to decide as an actor how you are going to give a character presence. You can't really move, walk, and talk like yourself. This creates something so you have to find something "other".

I have an enormous amount of respect for Nicole Kidman. She's just done so many great movies and she's been out there at the forefront of carrying films and being a movie star. On set, it really pays dividends because when you're performing with her, she knows exactly how to play it. You don't have to compensate for her in any way.

I just invited close friends and family, the usual suspects whose opinion I value but who I know will enjoy the film [Before I Go To Sleep]. I don't know how difficult it is for them to suspend their disbelief because they obviously know me and what they're seeing is not me.

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."

In the movie, you have to decide as an actor how you are going to give a character presence. You can't really move, walk, and talk like yourself. This creates something so you have to find something "other".

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.

And I think in your 40s, you land a little bit, physically and mentally, you arrive at a place where you feel you've learned some stuff. Having children at that point meant I had something very useful to do for the next 20 years.