It was tough playing the young Sir Ian McKellen. I had to spend some time studying his voice. I just wish we'd had some scenes together. Maybe we will in the next one.

My super power would be flying. If I can move metal around too then great, but flying would be the best.

It was pretty hectic during filming. Nicolas [Hoult] and James [McAvoy] went out and bought BB guns for everyone, so for five or six weeks there was a war going on. One day I was hemmed in in my trailer like Ned Kelly, with James trying to come in through the sky light. Nick got me in the neck through a crack in the door. Eventually they took away the guns because Josh Helman had too many injuries on his face.

The best age to be? 33.

The process for me is always the same. You try to tell a story, you try to do justice to the character. The only difference is you move more slowly making the blockbusters. With smaller films the money is tight. I like the pressure of working fast.

My most challenging role? Shame. That was pretty full on.

If you're going to do a job, do it properly. And treat others as you'd like to be treated yourself. That's the best pieces of advice I've ever had. The usual stuff.

I relax by going karting. I'm rubbish at it, but I enjoy it. That's the main thing isn't it?

In my fantasy world I'd be a Formula 1 driver in the early 80s. That would be pretty cool. But in reality if I wasn't an actor, I'd probably be working behind a bar.

Jesus Christ. That's the man I'd like to take for a drink.

My approach to style? Always dress well [laughs]. I'm a jeans and t-shirt guy. And I do like a good tracksuit. Comfort is high on the list.

The best thing about fame is getting to work with the best people in the business, and doing blockbusters so I can help fun smaller films that wouldn't get made.

The worst bit? I used to love to people watch. That's getting harder to do now.

The X-Men: Days of Future Past is out in cinemas Thursday 22 May.

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MORE WHAT I'VE LEARNED:

Keith Richards
Ralph Fiennes
Forest Whitaker
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