In order to deceive others, it is necessary also to deceive oneself. The actor playing Hamlet must indeed believe that he is the Prince of Denmark, though when he leaves the stage he will usually remember who he really is. On the other hand, when someone's entire life is based on pretense, they will seldom if ever return to reality. That is the secret of successful politicians, evangelists and confidence tricksters—they believe that they are telling the truth, even when they know that they have faked the evidence. Sincerity, my dear Julia, is a quality not to be trusted.