[Its nearest rival, I discovered, is The Last Question by science fiction maestro Isaac Asimov. This is the one about what happens when all the stars burn out. Is entropy reversible?] It is a curious fact that innumerable readers have asked me if I wrote this story, ... They seem never to remember the title of the story or (for sure) the author, except for the vague thought it might be me. But, of course, they never forget the story itself, especially the ending. The idea seems to drown out everything else - and I'm satisfied that it should.