Discipline. For some that's an ugly word. It conjures up thoughts of your parents grounding you for sneaking out of the house, or getting detention for cutting class. I'm not talking about the kind of discipline that is generated by others. I'm talking about self-discipline. The kind 15-year-old tennis star, Coco Gauff (photo above), requires to play tennis as well as she does. I mean she started playing tennis when she was 7 years old. That's only 8 years on a tennis court!