I just remembered a funny story from my 10th grade year. Not really a horror story, but to an excessively shy 15yo, it was the definition of that at the time:
You know how schools have rotating class schedules. But not a nice, sensible M-F one, that odd shifting 6 day rotation ...
The morning announcements were ingrained in my head:
"Good morning, Today is Tuesday, June 25, 2019. Today is Day 4, operating on bell schedule 1."
What IS Bell Schedule 1 anyway? We were ALWAYS on Bell schedule 1.
One morning I was late to school, can't recall why. I walked in late after being dropped off, checked into the office with my note and the receptionist stamped a hall pass for me and said "It's class 4".
No problem. Class 4 was English. Went to the locker, then back downstairs to my english class. Opened the door and froze .... it wasn't my class... O_O
Okay, it must be Calc. Booked it across the school to my math class, passing by the guidance office on the way. Looked at the wall to be sure their board displayed the correct day, okay, it was... Opened the door to my class and froze again .... it too wasn't my class. In fact it was my brother's class. The kids, were all laughing at me.
Why was it whenever my brother was anywhere I was, everyone would laugh at me?
Went back to the guidance office, desperate to figure out what schedule we were on, and what class I had. Usually there were at least two adults there but the department was empty. I paced in a panic for 10 minutes. Stopped back in the main office, she was busy with other students. I ran back to the English department thinking I simply did something wrong, nope.
Finally, just as I resigned to being hopelessly lost, that one friend who reached out to all the misfits in the school to make them welcome into a group called out to me. It was Aleece

The feeling was one of warmth and "I'm home." She told me I was supposed to be in French (She only knew this as her best friend and I shared that class).
I never did figure out why I was mixed up, nor did I ever get lost like that again. There was no reason for it, it's just the pieces weren't fitting together to match up with what I had on paper and when that happens I panic. I can only imagine it had something to do with being on some new meds(?).
That nightmare gave me a glimpse of how awful it has to be for dementia patients as nothing seems to fit what they're thinking anymore. (My dad always wants to get in the car and "go home" even when he is home, it's so sad.)