Randomly, my brain started singing the children's rhyme "Where is Thumbkin" the other day. There wasn't anything particularly pressing, so I sang it all the way through. If you don't remember it:
This is then repeated with the pointer, middle, ring, and pinkie fingers, each one bowing or nodding to each other on both hands. It occurred to me that this was more than just a children's rhyme to identify fingers - it was a story of how to properly check in on your introvert friends. The singer goes looking for their friends, says hello and how are you politely, and then leaves them alone because that's what introverts need!
Or maybe it's just a children's rhyme...