In which we learn that the more we teach about psychology, the more we speak about it, the more it enters our lives, and then we even start believing some of it ourselves. We discover something about the ease with which theories of personality can be put to work, and about the dangers of teaching people how to improve their interpersonal skills in order to become good psychologists. The seventeenth-century mathematician and religious philosopher Blaise Pascal argued that one needs to kneel and pray, and then belief will follow. Belief in all manner of outlandish ideas can be secured by forms of practice, and that indeed is how psychology as a discipline often functions, as I was to learn as I stood in front of the lecture theatre and spoke about theories of personality. The form and content of psychological theory as an academic practice has consequences for every individual involved in it, whether that is the student who must listen to me and show that they understand what I have told them, or whether it is their teacher. I want to show you in this chapter how I could not but become part of the very didactic system of ideas that I was so suspicious of, and how they worked their way into me as I described them.