One thing that puzzles me (and I use puzzle here in the technical sense of really, really irritates me) is reading, as from time to time I have, learned academic books on folktales and fairy stories that explain why nobody wrote them and which go on to point out that looking for authorship of folktales is in itself a fallacy; the kind of books or articles that give the impression that all stories were stumbled upon, or, at best, reshaped, and I think, Yes, but they all started somewhere, in someone's head. Because stories start in minds--they aren't artifacts or natural phenomena.
One scholarly book I read explained that any fairy story in which a character falls asleep obviously began life as a dream that was recounted on waking by a primative type unable to tell dreams from reality, and this was the starting point for our fairy stories--a theory which seemed filled with holes from the get go, because stories, the kind that survive and are retold, have narrative logic, not dream logic.
Stories are made up by people who make them up. If they work, they get retold. There's the magic of it.
Neil Gaiman, Fragile Things