Cohen grew up in St. Louis, Missouri, in a Jewish family. His parents divorced during his early childhood. Cohen barked and twitched constantly during his waking hours, and would knock his knee against the inside of the car door. Someone asked his mother once if she had considered an exorcist. His mother was compassionate, but his father did not understand why his son did the things he did, often getting frustrated and punishing him for making noises or other physical tics.