Today, we all generally understand that the brain is responsible for what we call personality and thought -- yet this wasn't always the case. Once humans figured out the brain was more than a weird lump in the skull, it took centuries of trial and error, along with quack science, to really understand how it works. In today's episode, the guys welcome back special guest Jorge Cham, the creator of ScienceStuff, to lear more about the ridiculous history of brain science.