Noel Gallagher himself writes on the Oasis site what this song is all about.
"Some of the lyrics were written when I was out of it. There's the words: 'Someday you will find me/ Caught beneath a landslide/ ln a Champagne Supernova in the sky'. That's probably as psychedelic as I'll ever get. It means different things when I'm in different moods. When I'm in a bad mood being caught beneath a landslide is like being suffocated. "