If you knew, then you'd be lying in the street too...
Nobody knows. We're not supposed to know. Or rather, we have been spared the information. Information is a curse. We all want to know more and it will do us no favours.
I've heard that he says 'It is better to lie down than to stand up.'
Or possibly, ' "The Bends" is a far superior album to "OK Computer", and the only reason it is generally thought to be better is because people jumped on the bandwagon a bit too late. Lie down if you agree with me.'
See you on the pavement...