This reminds me of a story my wife told me, but I also found it on this blog: https://www.apraksinblues.com/apk-article/master-lius-judgement-this-grandfathers-beard/

There once lived a old man who had a long mustache and beard. He had a wonderful appetite and slept soundly at night. One day his grandson asked him, “Grandfather, when you go to bed, where do you put your beard — under the blanket or on top of it?” The old man had never thought about this, so he couldn’t answer his grandson. But in the evening, lying in bed, he tried to decide how, indeed, it was better to sleep: with the beard under the blanket or on top? All night, he tossed and turned and couldn’t sleep.