If I have a dream and focus on remembering it once I've awoken, I can create a facsimile of it even though the original idea is all but gone.  One of the dreams I've held onto in this way is one where I'm in space, on some sort of space-station like structure made of gold, that's really a lot like a giant Escher structure.  Swarming this structure are dark, shadowy creatures, and while I can almost fly, I can't quite.  I'm forced to drift down slowly, land on the structure, and then leap into space again just barely escaping the monsters, but the gravity of the structure always pulled me in again.