for some reason i'm thinking back to a stupid lesson from like kindergarten, where the teacher had salt in a bunch of pots and one pot of sugar. each student was supposed to pick a single pot to get a spoonful from, and eat it. if you got salt, you weren't allowed to guess anymore.
thing is, the pots weren't identical. they were a matching set but they looked slightly different from wear and tear. so i could tell which ones were which even when they were shuffled.
i think the lesson we were supposed to learn was about probability i think? but after getting it right 5 times in a row by seeing which one was which the teacher made me stop guessing and the only thing i learned was that i was surrounded by blind morons who couldn't figure out the obvious even when it was right in front of them (teacher included)