Henry Ford? Jessie Potter? Dayle K. Maloney? Cathy Bolger? Susan Jeffers? Jackie “Moms” Mabley? Tony Robbins? Anonymous? Dear Quote Investigator: Why do people repeat foolish, ineffective, or self-destructive behaviors? Self-help books contain an adage about the consequences of thoughtless repetition. Here are three versions: 1) If you do what you’ve always done you’ll get what …