"X-Men" is not really about mutants; it's about humanity. I think it's about the human race. We're an absolutely destructive race. It seems that we can't seem to get beyond this level of tribalism that has been around for thousands of years. Anything we fear we tend to destroy.

We feel a lot of pressure about looking silly or appearing weak, whatever that means, or being a failure. You have to keep in your head: what's the worst that can happen?

I'm always interested in trying to investigate different personalities. I want to keep myself guessing and keep the fear element alive, so that I don't get too comfortable.

If you're dealing with a character that actually exists, there's an awful lot of information there. So, you can put together, from the information, motivations, insecurities, reactions. Where does that seed get born, if you like?... What I do is put that together.

Big things have small beginnings.

[As an actor] I have ideas, but things should always be fluid. You should always be ready to follow an instinct. Something might reveal itself on the day.

You use words like 'introvert' and 'extrovert,' various traits of a personality. A lot of that stuff, we used in drama school, and that was kind of interesting, to realize my teachers sort of ripped off a lot of Jung. And how much of it is part of our society now, these phrases, introvert and extrovert, where it actually came from.