" Believing-a-lie mistakes occur because certain people just don’t make mistakes when they lie. These are not just psychopaths but also natural liars, people who are using the Stanislavski technique, and those who by other means succeed in coming to believe their own lies. The lie catcher must remember that the absence of a sign of deceit is not evidence of truth. "

― Paul Ekman , Telling Lies: Clues to Deceit in the Marketplace, Politics, and Marriage