Last night I had a dream that was so real that when I woke up I came downstairs to feed the fish that were part of the dream.
The dream was about a fantastical hidden room in my house.
I don't think that I have ever had a dream so real that I tried to react to it in waking life.
Occasionally, Set gets into a bit of trouble for the things he does while I'm dreaming.
Some of the books seen in The Library of Dream in The Sandman by Neil Gaiman. These are all, or nearly all, real authors, but the titles given never existed (though in most cases they are closely related to or play on real-world titles by these authors).