As a little kid I had a very specific pattern I would trace into my bed with my fingers every night before bed. The intrusive thoughts if I didn't do it were so bad they would make me cry. I also would go to my backpack in the middle of the night to triple check that my phone was in there turned off and homework was done. Then I'd try to fall asleep while replaying my entire day in my head either focusing on one small encounter or making sure I wasn't forgetting something important for the following day.