Okay, this was kind of weird.
I was lying in bed late last night, sort of drifting off. Upstairs there were sounds of a loud party: stereo up high, a lot of people talking. Besides being annoying, this struck me as very unlikely. The building is all studio apartments. There's not really room for people to throw parties. On top of that, the landlords are emptying the place out, and most of the tenants have already moved away. So who were all these people?
Since it looked like they'd be keeping me up for some more time, I changed positions, rolling onto my back. Right away, the noise disappeared. Which is to say, it never existed in the first place. While I was still at least partly awake, I was also asleep enough to dream about the sounds of this get-together.
It wasn't an entirely pleasant experience, but kind of cool nonetheless. The way you can just conjure things out of your own head.