Og Mandino's The Greatest Salesman in the World asks one of the oldest questions in self-help literature — what separates the people who succeed from the people who don't? Mandino's answer, delivered through a parable set in the ancient Palestinian city of Bethlehem, is that the difference isn't talent, isn't intelligence, and isn't opportunity. It's habit. Specifically, the kind of habits formed by reading ten ancient scrolls, each containing a single principle, three times a day for thirty day...