Ok, in the first Beatles movie, A Hard Days Night, there is this kind of melancholy scene where Ringo is walking along a river. There are some boats in the river and for no apparent reason he turns to them and shouts "come in number 51, your time is up"

I had gotten really high last Saturday and was watching that movie. When he said that I knew I had heard that somewhere else before. I hadn't listend to it for at least a year but, by pure coincidence, on Sunday morning I pulled out the Pink Floyd Relics cd. I looked at the songs and the very last one was "Come in number 51, your time is up" Instantly the light bulb went off over my head.