A couple of commenters answering my question about purgatory (two entries down) refer to J.R.R. Tolkien's story "Leaf By Niggle." I haven't read the story myself, and it's not online, so one would have to go to an actual library (gasp!) or bookstore to find it. On the other hand, for those who do know the story and want to read more about it, there is, of course, a "Leaf By Niggle" fan site.