When I started school, I had an elderly teacher who in my view should have been enjoying her pension instead of teaching a prep class. She was just too far past it. She would walk around the room looking at what the class was doing and without any warning, smack the hand of some student for the most trivial thing.
Once during a writing exercise, I remember my hand shaking uncontrolably when trying to form letters of the alphabet, worrying that I would be smacked because my writing wasn’t perfect. I have memories of kids who had poor learning skills being mercilessly targarted by this teachers ruler or strap.