I found this at a nearby public library, sticking out between two books in the medical section. My guess is somebody wanted it to be found. They got their wish. (If you look closely, you will see that it’s not drawn with an ordinary #2 pencil, the lead is thicker.)
I found something a few years ago inside one of my text books for a class on love and relationships. I found it again a few days ago, it couldn’t have been a more appropriately timed rediscovery.