Why do brains generate strange thoughts sometimes? And why do some brains refuse to let go of those thoughts? Today we'll talk about Obsessive Compulsive Disorder (OCD) with expert Jon Hershfield, getting a view from the inside and the outside. Why do some people lock the door but go back repeatedly to check it, and still have a feeling of uncertainty that it’s locked? Why do some people wash their hands over and over and never feel that they reach a point when it’s “done”. How, for some people, are intrusive thoughts like junkmail that the brain just cant help opening? We’ll see how obsessive thoughts can get caught in loops, and how those loops might therapeutically be broken.