Do you find it frustrating when people say Wolverine has overshadowed your career given your range of work on stage and screen?
“Not really, because if I want to play a certain character I could. But I'm surprised pretty much by everything that has happened in my career.
“I was hoping to pay the rent as an actor one day and before I was an actor I was acting at the amateur musical society. I never thought I would make a career out of it. So if it stopped tomorrow I would probably go back to the amateur musical society.
“I'm someone who always tries to remember how lucky he is. And even if it's only Wolverine, it's pretty good.”
Were you worried when reports came out claiming you were being offered huge sums to do four more Wolverine films?
“Yeah, because obviously it is bull***t. It was the National Enquirer. I couldn't believe anyone picked that up. Apart from the first movie, for which I had to sign a two-picture deal, I've never done more than one at a time.
“And now what happens is the IRS and every taxation company goes, “Hang on, you didn't declare $100 million. So where are you hiding it?”
You recently received some lifetime achievement awards, are you still looking forward rather than back?
“Sometimes I say to my wife that maybe they're giving them to me as in, 'Please stop. That's enough of your lifetime. If we give you this, will you just go away?'
“I haven't told anyone this before but when I was auditioning I had this superstition that you can't ever repeat a monologue that you've done, because I was afraid that I would just do it as I always did it.
“It's tempting, sometimes, to fall back on the things you know you can do or the things you know have been successful, but you've got to keep trying to do different things and risk failing. Hey, look at Movie 43.”
I'd rather not
“Or don't [laughs]. I ran into one of the producers a little while ago and he said, 'Mate, I've got two things to say. I'm sorry. And, I'm sorry.'”
It was just a day of your life
“It was two days. With Kate Winslet with balls hanging from her neck. It wasn't that bad.”
Your Prisoners character, Keller Dover, is a pretty tormented guy. Was he tough to play?
“I don't stay in character but I can't say I was fully relaxed at the end of a day. It's a weird thing. Acting is like the greatest privilege: you get to inhabit lives and you get to touch real emotions, and at the end of the day you're calm, like you've had a great bath.”
He's driven mad by his daughter's abduction. Did having kids yourself mean you were able to go deeper into the character?
“Probably. I always like to think as an actor, arrogantly, that you can play anything. But just reading the script, I felt it in the pit of my stomach.”
You have said you're not materialistic. What do you do with your money?
“My wife has taught me a lot about money. We didn't have any when we first met. I was at the Royal National Theatre earning £375 a week and we were as happy as we are now.
“Money doesn't make you happy, and I know that. And sometimes I get embarrassed by it and sometimes I feel burdened by it.
“My wife's line is, 'You've got the wrong attitude about money. Money is energy and there's no point trying to save energy. You use it and you give it away.”
You have been married a long time for a showbiz couple. What is the secret?
“I'm almost positive 80 per cent of it is finding the right person. And when you're lucky enough to meet the right person you just know it 100 per cent.
“Like all couples there's strains and there's compromises, but she's honestly the greatest thing that ever happened to me.”
Finally, you've been working with the original X-Men director Bryan Singer on X-Men: Days of Future Past. Is it different playing Wolverine with him than it is with, say, James Mangold, who directed The Wolverine?
“It's always special for me working with Bryan on this character. He gave me that break, he gave me that character, and I can't believe, 14 years later, we're working on it again.
“He's a great friend, and he's a very smart man. I can tell you right now, he has made a great movie. I don't know if it's going to surprise people but I think people are really going to like it.”
Prisoners is released on DVD on February 3