Before mirrors were invented, almost no one had ever seen their own asshole
Before mirrors were invented, almost no one had ever seen their own asshole
It would be common to see still water and your own reflection
Less common that someone would position themselves in such a way they can see their asshole clearly in it without disturbing the surface.
What do I know? Maybe they made little foot jetties just so they could stand above the water and gaze wistfully in into their own rectums on still days?