I'm only part way through this book, but I think I have an idea where the author is going. It's interesting; instead of the oh-so-very-earnest stuff you read from people who are trying to 'prove' to you that out-of-body experiences exist, this author posits the possibility that there are things going on that could be known, but science has no interest in them. So he reports, and invites you to think what you like.
Now for why I think this could be a 'sleep' topic, my SO is a person with many, varied, vivid dreams, with full plots and characters. Sometimes I wonder how merely going to sleep could set free such a rich imagination; is it possible some of these experiences are real, but in dimensions we currently dismiss?
I am not good at remembering dreams, though I'm certain I often do dream. And once in a while I'll remember part of one. What I often remember is dreaming of flying, or near-flying (descending long flights of stairs effortlessly, touching down on maybe one of ten) and I've had some hair-raising takeoffs.
What do you think? Is there a 'world of sleepers' where real things happen?