happened to me at age 7(?) - I remember the grade and room, just not the date.
it was one of those things that chipped away at my respect for authority - it didn't destroy it, but still dinged it. Peers still turned on me - no one thought "it could be me next". We were 7/8(?) - I'm not sure most people could reason that far ahead vs living in the moment.
What sticks with me is that we had an announcement earlier (few days or weeks earlier?) that no bathroom breaks would be given out because a few kids had 'abused the privilege' (stayed out of the room longer than they should have). So... someone else violates a trivially stupid 'rule', and my own life is negatively impacted, which is wholly unjust. That was my takeaway, which has stuck with me for ~40 years. I still remember a couple of the kids who'd been 'abusing' that privilege beforehand, and remember what impact they and that teacher had on me that day and beyond.