Back in highschool I was trying to find the room for a catchup test after class, when everyone else had gone home. The teacher who gave it to me didn't specify what room it was in so I was just walking around complaining to myself about my stupid teacher. I reached the end of a hall and turned around, only to notice a boy at his locker who was frozen in whatever he was doing and just staring at me. I wasn't really sure how to handle the situation from there so I kind of froze up. After about 10 seconds I realized I had to do something so I gave him a really big smile and slowly walked away without breaking eye contact.
I have never talked to myself since.