I wish I could upvote this more than once. I have never thought about this exact issue but I have written quite a bit about a very similar topic when I was in college. I studied literature and I was quite fond of writing about the pseudo-divine power of authorship. When one creates a fictional character, that character and his or her world are born into existence first in the mind of the author, again on paper, and again in the mind of a reader. That character or story can and does have an effect on the real world because they can influence a reader. In this sense, these things born out of thought become real. I particularly like to read Paradise Lost through that interpretive lens because when you do it becomes far more subversive than it already is. Milton, himself, becomes God (within his own little paradise) and Satan's lies become deceptive truths (in book five, anyway) which would have probably pissed off those 17th century puritans if they had picked up on it.

Anyway, I will stop rambling at you. Good post.