When I was very young (around 3 or 4) I woke up in the middle of the night and went downstairs to climb into my parents' bed.

After some time, I could see a small-scale but very extensive science fiction space base on top of the bed covers, as if the bed covers were the surface of a moon or planet.

It was populated, and in motion - rockets launching from gantries as I watched, etc. I know it wasn't a dream, because my parents remember me describing it to them as it happened.

I've never experienced anything like that again, and never heard of anything like it until reading about these mushrooms last year.

It definitely seems like an odd quirk of the brain that it apparently has a ”1990s god video game" (e.g. Populous) visualization mode.

There's some neat sci fi novel potential there, though, like it being a remnant of some kind of distant ancestor with a hive mind that could synthesize the visual input of multiple members into a disembodied third-person camera point of view.

Same thing here. About 8, Mickey Mouse, 2D, 3-4" high, dancing on the back wall of a tent (in the middle of the forest). Have never had another hallucination--that I know of.