I have been working for Africans since I was 18, when I got involved with the Nelson Mandela concerts. I got involved with debt cancellation because Desmond Tutu demanded that the world respond to that situation.

I'm never nervous when I go to meet heads of state. I feel they should be nervous, because they are the ones who'll be held accountable for the lives their decisions will impact the most.

It's much easier to be successful than it is to be relevant. The tricks won't keep you relevant. Tricks might keep you popular for a while, but in all honesty, I don't know how U2 will stay relevant. I know we've got a future. I know we can fill stadiums. And yet with every record, I think, 'Is this it? Are we still relevant?'

Contrary to reports, this boy is not a billionaire or going to be richer than any Beatle - and not just in the sense of money, by the way. The Beatles are untouchable. That’s just a joke.

Because you know when you first become famous, you start walking a little different because people are staring at you.

Facebook are an amazing team, a brilliant team. It's a technology that brings people together.

Selling out is doing something you don't really want to do for money. That's what selling out is.