Someone asked me what “Champagne Supernova” is about. I was like, “Who gives a fuck what it’s about?” And he’s going, “But surely when you write it you must know?” On stage, two hours later, in Scotland, with an acoustic guitar, I’m playing it and there’s a 15-year old kid, he’s got his top off and he’s singing it, crying his eyes out, and I’m thinking, “That’s what it’s about.”