It’s about how the self studies itself, and loses itself. My starting point is the embodied sense of self. I wrote it precisely against the Cartesian framework that prevailed for so long in philosophy and cognitive science. I wanted to understand what is going on when we lose track of who we are. So I ended up sitting in on the weekly clinical sessions of patients in a neuropsychiatric unit at a Paris hospital, and was privy to the examinations and medical discussions. The patients consulted there because they had diagnoses that were ambivalent or unclear. I picked out of the many I saw those that presented something most interesting with regard to the sense of self. To try to understand these people I drew on cutting edge work in psychology and neuroscience about the embodied sense of self, particularly in relation to interoception.