wasn't anything paranormal/supernatural, but I think the creepiest surreal experience I've had that wasn't "supernatural" was when I was 15 and going to see my partner at the time. There was a wooded hide-out that was close to a place I used to live, mostly just a shitty "natural park" that was a thinly-disguised dumping ground with a river through it in urbia.
anyways, I was meeting up with her there and while walking through I see two girls around the same age (looked like at least) that were IDENTICAL in appearance along the little wooded pathway heading to where we usually hang out. Like, only difference being is the shoes and some minor make-up but the same hair, facial features, height, etc; guessing they were twins. They both had straight up red eyes (they were high) and were breaking into fits of nervous laughter upon seeing me and walking in pace. I literally just don't say anything until I get to her where she was sitting by a collapse concrete sewer main that was ripped out years ago and she just starts laughing after I ask her "What the actual fuck was that?"
Apparently it was some twins that were hanging out in the same area, they tried some weed she was smoking and they both lost their shit. I just happened to be walking in when they were both collectively losing their shit and leaving. What's crazy is that they were laughing and walking in unison at the same time.
I was also mildly stoned at the time and was just pretty much paralyzed in fear and keeping my distance while I walked by them. I literally thought I was entering a horror flick a la some "Shining" shit or something.