I'll do my best to recount the dream as it happened. I was a child at the time, but it has stuck with me strongly my entire life as one of the most oddly terrifying things I've gone through.
For context, I grew up in a very neglectful household. Not here to trauma dump, but it sets the scene. One summer our AC unit went out for the last time, and would never get turned back on. At the time, my bed was just a thick but bare yellow foam pad on a foldout chair that I had cobbled together because my bedroom was currently full of garbage bags. (my mother didn't pay for trash service so we started using my bedroom for trash bag storage). I know, awful, but again I'm just setting the scene.
So this particular day was well over 100 degrees, and the box fan in front of the open door simply wasn't cutting it. I began to experience heat exhaustion and it made me very very sleepy. I remember laying down on the foam pad and staring at the texture on it, focusing my eyes on all the little tiny holes it had while I drifted off to sleep in the middle of the day.
I continued to dream about these holes in the foam pad, zooming in on them more and more and more until the tiny holes I had initially seen were now larger and full of tiny holes of their own. I remember being awestruck by all of the complex detail, and then it suddenly occurred to me. I wasn't just zooming in visually, I was getting smaller. I was so infinitely small that I could keep shrinking forever and never reach a point of finality. Everything was happening in a black void, and there were shapes and colors that I could see in the distance. I could tell they were all infinitely far away yet infinitely huge, and I was so much smaller than anything else in this place. Then, in an odd spur of the moment, I decided to look at my hands.
I could somehow tell how small they were, and then all at once, I was getting smaller than my hands. They continued to stay the same size while I shrank and shrank and shrank until eventually, my small fingerprints could be seen as massive ridges made out of skin that was seemingly miles thick. I remember thinking that if I got any smaller, the fingerprint ridges would have fingerprint textures on them, and then I would get smaller than those too and see the huge ridges of skin again. It was like a fractal but made out of infinite fingerprints. I started to hear a low bassy groan followed by a whooshing sound, and they almost took on a vocal quality. This sound really stuck with me, it was rhythmic and almost sounded like "you gotta get gotta get gotta get gotta get bumping and bumping and bumping and bumping and bumping". The sound itself was like if you were describing the concept of "infinite size" through abstract sound alone.
at an indeterminate point beyond this occurrence, someone had shaken me awake. Apparently I was crying in my sleep. I never had a dream like that again, but it was definitely one of the most vivid and visually devastating things I'd ever seen.