"Last reason for reading horror: it’s a rehearsal for death. ..." — Stephen King quote meaning

Last reason for reading horror: it’s a rehearsal for death. It’s a way to get ready. People say there’s nothing sure but death and taxes. But that’s not really true. There’s really only death, you know. Death is the biggie. Two hundred years from now, none of us are going to be here. We’re all going to be someplace else. Maybe a better place, maybe a worse place; it may be sort of like New Jersey, but someplace else. The same thing can be said of rabbits and mice and dogs, but we’re in a very uncomfortable position: we’re the only creatures—at least as far as we know, though it may be true of dolphins and whales and a few other mammals that have very big brains—who are able to contemplate our own end. We know it’s going to happen. The electric train goes around and around and it goes under and around the tunnels and over the scenic mountains, but in the end it always goes off the end of the table. Crash.