So, like a reasonable percentage of the population, I occasionally experience hypnopompic hallucinations - during the transition from sleep to wakefulness, I'll occasionally have a vivid perception of something that isn't there. Usually accompanied by sleep paralysis.
In the past 6 months or so, I've experienced 2 instances of a classic of the hypnopompic hallucination repertoire - a sense of a dark and rather menacing presence looming near the bed. According to what I've read online, this is a very common hallucination, and people tend to attribute it to whatever supernatural or paranormal entity is most plausible in their culture: ghosts, alien abductors, incubi and succubi, etc. (I'm rather thankful that my illusory intruders are of the polite sort, and don't come and sit on my chest.)
The first time this happened to me, my brain convinced itself that someone had broken into the house, which was pretty damn scary.
Last night, when it happened again, my brain decided that the appropriate shape to clothe a dark and vaguely menacing presence in was that of a black metal musician, complete with the corpse paint and the spiked gauntlets, etc*. The last thing I can remember thinking before waking fully was, "Look, I don't care how cool your new album is, you need to get the hell out of my bedroom until I've had a chance to get dressed."
I'm kind of amused by the idea that regular exposure to the play-acted "evil" of black metal imagery may have effectively inoculated my brain against the scary elements in its own inventions. It'll be interesting to see what my brain comes up with the next time this happens.
*It would have been really cool if I could actually claim that it was the drummer of Inquisition, who actually goes by the stage name Incubus, but my brain isn't quite that clever.