On a Sunday morning in 1963 Theodore Millon woke up in a Pennsylvania hospital. He was in bed at a psychiatric ward shared by 30 patients. One of them thought he was Jesus Christ, another believed he was the pope, and a third claimed he was a corporate CEO who had been hospitalized by mistake. Millon began to fret. "I am wearing a hospital gown like all the other patients," he thought. "Am I really a professor of psychology? Or did I just imagine that?"