As a pre kindergarden child my room was directly across the hall from the bathroom. The door was always opened at night and there was a dim night light. There was some "feature" thing that looked like a it should have been in a garden as a trellis for plants to grow up.

One night, I woke up and saw a small elf looking thing climbing up the trellis in the bathroom. It seemed like I watched it for hours but even though its little arms and legs were moving in a climbing motion, it never seemed to get any higher.

Another occasion, a few days after I had bought the NES Legend of Zelda from a pawn shop, I came down with a fever bad enough to have some very messed up dreams where I was inside the game as Link. Playing through the parts of the game that I had managed to get through before I came down with the fever. It was incredibly realistic, to the point that when I got well enough to actually sit down and play the game some more I was confused that I didn't have all the stuff I had collected in the dream.