Waaaaaaaaaaaaaaay back when I was a young'n, when I first got Super Mario 64, I had trouble figuring out how to get the Behind Chain Chomp's Gate star. After I gave up figuring it out, I started thinking of ways to get to the star, and fell asleep doing it I guess. Not knowing what a Ground Pound was, I dreamed about being able to clip into the gate in some fashion, long before I even knew what clipping even was. Somehow I made it in, but boulders started showing up and I had to make Mario jump over them in the tight space. Of course, that wasn't how the game actually goes, but I learned how to do a Ground Pound and deal with Chomp soon after.
Later I dreamed Mario was jumping between two stone pillars in the middle of a large pool of lava, both with a star over them. I don't remember what happened in that one.