There are many definitions of self-discipline, but I prefer the one given by the American philosopher and writer Elbert Hubbard. He said that self-discipline is "the ability to do what you have to do when you have to do it, whether you feel like it or not."
Self-discipline is a crucial life skill that allows you to succeed in whatever you choose to do. Again, this doesn't necessarily have to do with money. It may have to do with your relationships. It may also have to do with your health.
As you probably already know, if you're like most Americans, losing weight is no joke. It requires a tremendous amount of self-discipline because, hey, let's face it, when given a choice, we'd rather eat pizza. We'd rather munch on a burger or enjoy some fried chicken. But it takes a lot of discipline to eat salad day in and day out.
Self-discipline allows you to concentrate
When you are self-disciplined, you learn to keep your focus trained on your priorities. You decide your goals and prioritize what is most important on a daily basis.