If Bono left, we could carry on. If I left, we'd be screwed.

I've often thought that it would be great to do some acting because nobody would think that I would be able to do it and it scares the living hell out of me.

Relevance is a big, big question. It's more about what's your definition of being relevant. In the music world, agism is a big issue. It's about youth and youth culture. There's no other art form that I know that requires you to be a certain age.

And if I had to spend 20 years in the band just to play that show, I think it would have been worthwhile.

People say, 'Why don't you do interviews? What do you think about this? What do you think about that?' My job in the band is to play drums, to get up on stage and hold the band together. That's what I do. At the end of the day that's all that's important. Everything else is irrelevant.

There's a thin line between interesting music and self-indulgence. We crossed it on the Passengers record.

The big issue with rock stars becoming actors is that sometimes it's not believable, and vice versa with actors becoming rock stars. Sometimes just doesn't fit.