Those puzzles in the 90s which were really tricks… I remember one which had a rod-like piece and another piece to put it into. If you got it just right, apparently, it would catch on something and be pulled into the slot. Was it a magnet? An elastic band? You couldn’t see inside it, but that Guy could do it and one by one, others cottoned on, too.
Of course the trick was to realise that there was no trick except to squeeze the end of the rod with your thumb and forefinger until it was propelled into the slot and then you had to propagate the trick by pretending that you’d found the trick (which, of course, you actually had). As it was passed round the group, more people would get it and would congratulate each other and feign help to the rest who couldn’t until, eventually, marked out by their intellectual inferiority, they were killed.
Response to a writing exercise at work.