Bob Geldof's "greatest fear" was he'd end up homeless and destitute.
The 68-year-old rocker was just 15 when he began volunteering in a shelter to help those on the streets of Dublin and he admitted he was terrified he'd end up one day sleeping outside himself.
He said: "At 15, I vounteered t the Simon Community.
"My greatest fear was that I'd become one of the people I was working with, gathering around the big fire we had in Smithfield, taking the soup we were making.
"That was my image, at 60, sleeping on a park bench in the cold, so I had to keep running, keep running. And I can't stop."
The Boomtown Rats frontman admitted he can be "exhausting" company to be around and is amazed his wife Jeanne Marine - who he wed in 2015 after 19 years together - has "put up" with him for so long.
He told the Daily Telegraph newspaper: "I am exhausting. I exhaust myself.
"And to be around it in the domestic sphere is deeply annoying. I don't know how Jeanne puts up with me.
"I need to be constantly frantic and I keep going until my brain says, 'Stop, please!' And then I sleep.
"But then I worry and wake up again."
Bob's mother died when he was just seven years old, while his father was a travelling salesman and not often around and the 'Rat Trap' hitmaker thinks his childhood has left him without a proper understanding of "authority".
He said: "[I had] no polar centre of authority, parents from which you learn the parameters of what's allowable.
"And that's always been a thing, when I meet the Pope or a president. There's a part of you that doesn't understand what gives them authority."