“No one really knows why people made the rock art they made, at least in many cases,” Harman said

Well, it's obvious they really wanted to though. This isn't like marking on a wall with a Sharpie. They had to work at it to make it happen. The commitment alone is impressive even if it was just a "Grogg was here!"

https://smbc-comics.com/comic/rite-on

> "No matter what you do, when we find something weird in ancient history we will decide it must've been part of a fertility rite."