This song is about how time can slip by, but many people do not realize it until it is too late. Roger Waters got the idea when he realized he was no longer preparing for anything in life, but was right in the middle of it.

Death, the only immortal who treats us all alike, whose pity and whose peace and whose refuge are for all - the soiled and the pure, the rich and the poor, the loved and the unloved.

Mark Twain