My mum was convinced that going to sleep with wet hair would give you a fever lol, even told me. It’s a lie. She believed it because her mum told her.
One from my mum: My mum learned gardening from her grandfather and her nomenclature for the local weeds and plants was all in her grandfather’s dialect (thing like swapping the sound u with e etc), which was different from the dialect she grew up in (because she grew up in basically the town nextdoor). She was in her fifties when we discovered that if you replaced certain vowels etc within her garden vocabulary, that you would often get dutch words that actually existed and could be looked up on the internet. It really made discussing weeds a lot easier all of the sudden.
Edit to add: I was in my twenties when I discovered that the words I used for some weeds, were in a dialect from a man I had never met, from a village I had only visited once in my life :)