A little miffed by the ending

Obviously spoilers, but I didn't really like the way the ending happened. In theory, it's a really cool concept, but having that concept sort of kerplunked on you at the end stunk (imho). I don't think anything would have been lost and perhaps even improved, if there was some foreshadowing at foreward-projecting being required by the reader in order to put it all together. Nonetheless, I'm sure subsequent readings will be entertaining, but I think this first read-through kind of annoyed me at the very end.

Still, I have no way of imagining how to begin to write such a thing myself and perhaps this was the only way he knew how to make this book. It's really like nothing else I've read.