one of the strangest nightmares i've ever had was somewhat of a recurring one. it is also sort of difficult to describe. i guess i can start with a little context.
something else that scared me a lot as a kid was technology going "wrong" or "rogue," or becoming possessed even, or something else like that. creepypasta always got to me pretty bad for that reason, especially concerning video games. something about the idea of playing a game and having it go completely out of control or to find something i really, really was not supposed to scared the hell out of me. so, naturally, i had plenty of nightmares about just that. but one of them was always worse.
i've only had this dream a handful of times, even somewhat recently, but it always goes essentially the same way. it's hard to remember many details even now, but the first thing that seems to happen is that i find a strange game online somehow. it might be on accident or a purposeful curiosity, but i launch it anyway. there's something like a command line that appears, and you have to do something there. the text might be incomprehensible, but i don't know. another part of the game involves a sort of top-down RPG type gameplay, walking around this cavern type area, sort of like a maze.
playing the game, i always feel deeply unsettled and strange, like something terrible is going to happen. yet, i always reluctantly continue. but then, eventually, something happens. i think the point where it happens is different each time, sometimes you get put back to the command line part after doing the cavern maze and then it happens, or sometimes there has been this arcade machine at the end of the maze which upon being interacted with activates whatever it is.
regardless of when it happens, what happens is something i'm not sure how to describe. the one thing i know about it though is that it always gives me one of the most impossibly terrifying feelings that i think i've ever experienced in a dream or perhaps otherwise. it's just for a moment before the whole dream ends and i wake up, but it's like this powerful burst of fear and extreme uncertainty. like something so incomprehensible and infinite that you can't help but feel this overwhelming sense of dread and doom and terror. i don't know. but waking up from that always heightened my fear of going back to sleep, because i really, really did not want to experience whatever that was again.
and as a side note to that, one of the worst things about it after the fact was how alone it made me feel, and in the worst possible way. as in, it was so incomprehensible and hard to describe that i knew i could never really convey that to anyone, and thus could never really get any true understanding or comfort from it. it was one of those things that only you could ever know, and only you were up against and had to deal with. something about that total isolation always made the idea of having it again even worse. that's the horrible thing about dreams in general sometimes. there's no one but you around to help, and you're trapped inside your own mind until it decides to let you free. it can be an awful, awful thing.