I've had one. I had never used it before, and it's now recreationally legal. I ate a portion of an edible and fell asleep two hours later feeling nothing, then woke up at t+ 4 hours uncomfortably high.

I saw closed eye kaleidoscope visuals when I blinked, and it was messing with my sense of time and short term memory in a big way. Everything was happening in short micro-second bursts. My mouth was super dry, but drinking water made me feel like I was going to choke because I was somehow numb to my body but also hyper aware of it. Then I got really hard shakes for a few minutes.

I woke my wife up, and talked some nonsense to her for a bit, which seemed to help. I have a tendency for anxiety, and have had panic attacks often, so it's not a big shock. The biggest contributor to me was not feeling in control of my thoughts or actions, or thinking that I would do things I wouldn't remember, combined with a feeling of separation from my body (what if I forget to breathe because everything is happening so slowly?!).