Actor Nicolas Cage is the nephew of director Francis Ford Coppola. He's known for roles in Con Air, The Rock, Captain Corelli's Mandolin and Leaving Las Vegas, for which he won an Oscar. In Oliver Stone's 9/11 film World Trade Center, out now, he plays a policeman who gets trapped inside the rubble of one of the towers after helping people to escape.

This film must have been an emotional journey for you. What made you want to go there?
I was trying to find a way that I could apply my abilities to something that would be healing. Then I got the call from Oliver Stone and thought, ‘Well, this could be healing. This could be helpful.’ So I said yes immediately.

Did you worry you’d be accused of cashing in on a tragedy?
I’m very sensitive to that. I didn’t do this movie for money. I donated my salary to charity. I did this movie because I believe that these people’s stories need to be told. But I’m concerned about that issue and I think so far we’re keeping it from what it could have been. I don’t think it’s being promoted as a ‘for profit’ film but one that’s respectful of people whose family members died.

Didn’t you do some unusual preparation?
Yes, I went in a sensory deprivation tank. I happened upon the detail that these guys must have been in darkness at least some of the time. And when you think about going through all this pain and shock and fear and, on top of that, you’re in total darkness, well, I wanted to play that element. So I tried this Black Box. They use about 900lb [400kg] of salt to two inches of water. There’s no light and you float in there for an hour.

What was that like?
It’s like altered states. You can’t even hear anything because they give you earplugs. The first thing I had to do was to get on top of the fear. My heart was really racing and all I was thinking was how I wanted to get out. But then what was interesting was once I got past that and got control of my heart beating and my breathing, I just started thinking about the words ‘within you, without you’. I just started smiling, I don’t know why and then I kind of relaxed into it and felt like I was floating in space.

Was there anyone you were really worried about on 9/11?
I knew a chef who worked at Windows On The World in the World Trade Centre. He didn’t make it.

I knew a chef who worked at Windows On The World. He didn’t make it.

You took your surname from a comic book hero, John Cage. Who were your childhood heroes?
I had different kinds of heroes. None of them are very interesting but, yes, some were comic book characters. Reading comics was really how I learned to read. I don’t read comic books now. I mean, I’ve moved on. But they were interesting to me from the point of view that they seemed like pop culture myths. And I liked the old Greek myths, as well. I still like mythology and Jungian interpretation of mythology and Joseph Campbell.

Do you use those in your life?
Yes. No question. I think that you can tap into a mythology and use it. Right now, I’m very interested in Arthurian mythology and I think these things are there for a reason because they kind of become blueprints for human experience and going through different walks of life. I’ve reflected on mythology to try to comprehend what was going on in some little way in my own life experience.

Can you elaborate at all?
Well, that’s so personal and I’m not going to mention any names. How about we leave it at that? But I thought that the way Arthur dealt with betrayal was incredibly heroic. And that he was forgiving because he really had no right or no business to be married at that time in his life, because he had other things he was working on. So he understood why he was betrayed. I can see parallels in my own life with that.

Did making this film make you question your own mortality?
I’m always thinking about things like that. I’m always curious about what happens when we die. And I’d like to think that somehow the spirit goes on. I’d rather not think that it’s just about this.

You’re so famous these days. Do you still do your own shopping at the supermarket?
Of course I go to the supermarket. I just went and bought about 20 packages of Gillette shavers. I buy in bulk. And I used one this morning.

Are you good at dealing with fans when you get recognised?
Well, I try to make an effort to behave well. I know if it weren’t for my fans I wouldn’t be here so they’re very important to me. I know what it’s like to meet someone you admire and have them be a complete jerk.

Has anyone treated you badly?
Once, before I was famous, someone impounded my car and they weren’t very nice about it. It was an old car once owned by Dean Martin, which is ironic because I now live in his old house. They left dents all over it.

What’s with the Dean Martin connection?
They’re both coincidences. I didn’t know it was his car when I bought it and I didn’t buy the house because it was his house. It was about 3am one night and I was sleeping and I heard this faint voice singing That’s Amore. And I was like: ‘Please, I’m trying to sleep’... No, I’m kidding. What’s really weird is that was the theme song at the end of Moonstruck.

You seem to be working all the time. Don’t you feel like slowing down, maybe with a margarita round Dean Martin’s pool?
I try to make two movies a year. To me, that’s not too much. On top of that, I like to work. It’s part of my spiritual belief. I want to do something with my time that’s productive. I want to serve and I feel I’m serving myself and serving you by working. I don’t want to sit around by the pool luxuriating with a margarita. That’s just not what I want to do.