A brief Biology lesson to explain behavior

A gross oversimplification follows.

There are two kinds of embryonic development paths. There are the protostomes and the dueterostomes. In a protostome, the first opening created will develop into the creatures mouth. In a dueterostome it will develop into the anus. People are dueterostomes. At some point in development we were all just an asshole.

Some of us still are, and somehow they gravitated towards playing League of Legends.

Lesson over.