Bono admits he is "annoying".

The U2 singer - a keen political activist and charity campaigner - knows he makes it easy for people to dislike him but insists having an "ego" is an essential part of being a successful musician.

He said: "I can be annoying. I have a kind of annoying gene.

"As Delmore Schwartz said, 'Ego is always at the wheel.' It's just with rock stars, it's more obvious. The need to be loved and admired doesn't come from a particularly pretty place. But people tend to do a lot of great things with it. Ego, yes, but the ego is in everything human beings are capable of. Without ego, things would be so dull."

The 49-year-old rocker also claims he doesn't write songs about specific people, and instead chooses to focus on himself.

Bono - who is joined in U2 by guitarist The Edge bassist Adam Clayton and drummer Larry Mullen, Jr. - explained to The Guardian newspaper: "The villain is usually me. The hypocrisy of the human heart is the number one target. Rarely do we point the finger at anyone other than ourselves.

"U2 choose more interesting targets than other bands. Your own hypocrisies, your addictions we never pick the obvious. I think we make our enemies very interesting."