"I thought if I had made a record and played at the Royal Albert Hall by the time I was 25 then I would have made it," he says. "That motivated me. I don't think there's any way Iron Maiden could play there - we're too much for it. It's a small gig, maybe 5,000 people, but for me that was like the Americans wanting to play Carnegie Hall."

At the age of 63, he knows it can't go on for ever. "I'm the twilight of the band," he reflects. "I'm not a granddad but I'm at that age where people wonder how long I can keep going."