Oh, so those never stop? I’ve had those myself off and on, especially right after I graduated from college. “Oh, whoops, sorry, you gotta go back and take Chemistry.” “But I thought I got an A in Chemistry?!” “We don’t have any record of that…” I thought it was just stress, but if you think about it, we probably all have deep-seated fears of beurocrats.
Re: the OP, it’s mostly smells that do this to me, but occasionally a song on the radio will remind me of a moment from high school. The smell of diesel fuel and hot blacktop sends me right back to riding the schoolbus in middle school. Add cheap plastic (from the seats) and I’m practically convinced I’m actually still 11 with my knees propped up on the seat in front of me. The smell and feel of a bunch of old crayons sends me back to my room when I was a pre-schooler, around 4 or so. I had a big cookie tin to hold my crayons, and I loved sifting through it (fresh ones are nice, but don’t have this effect).