A reasonably well known cliché among fantasy novels where the fantasy world is accessed from the real one seems to be that at the end of the series some action is taken which seals the two worlds forever apart (perhaps to stop the publishers continuing to demand sequels), and those real-world inhabitants who have memories of the fantasy world gradually find those memories fading and eventually seeming like no more than a childish fantasy, or a dream.

(I can't actually bring to mind the name of any novel which did this, off the top of my head, but it feels like the sort of thing which wouldn't surprise me in the least if it happened at the end of any given book.)

Last night I had a dream involving a fantasy world, accessed from the real one through a doorway. At the very end of the dream I performed a magical action which closed off the two worlds from one another and turned the doorway into a cupboard – making sure to keep a couple of physical souvenirs so I'd remember it had really happened and not come to believe it was all a dream, because I knew that usually happened in this situation in books.

Then I woke up, and now (of course) I immediately believe it was all a dream. I suppose I must have lost those souvenirs down the back of the sofa or something.