Bono's activism helped him "save [his] own a**".

The U2 frontman has always felt like an "impersonator" but admitted he nearly lost himself in the 1990s so is thankful he eventually set his attention elsewhere and was able to use his fame as a way of helping others through his anti-poverty and AIDS awareness campaigning.

He told the Sunday Times magazine: “I’ve always felt like a sort of impersonator when it came to being a rock star, like I couldn’t quite fit the bill. But in the Nineties I might have gotten a little too good at it. I suppose I could have stayed in those plastic pants

“I would say that what people call [me] ‘saving the world’ was probably me saving my own a**. I think the betrayal would have been to just enjoy this — the fabulousness of finally becoming rock’n’roll people.”

Meanwhile, the 'One' singer admitted his 40-year marriage to wife Ali Hewson - with whom he has four children - hasn't always gone smoothly and they've had to put in "work" to get through some rough patches.

He said: “It’s not like our love was absent any dark undercurrents or briny water, [but] we got each other through those bits where it was hard to see where we were. Ali calls it ‘the work of love’.

"I wish she wouldn’t use the word ‘work’ because I have a feeling there’s an adjective, ‘hard’, that’s inferred.”

The 62-year-old musician finds his wife "endlessly fascinating" and admitted neither he nor his children fully understand her.

He said: "Look. She’s incredible. She’s not just a mystery to me, by the way. She’s a mystery to her daughters, to her sons. I mean, we’re all trying to get to know her. She’s endlessly fascinating. She’s … full of mischief.”