As an athlete, you want to excel in whatever the game demands. In addition to the physical demands, you'll learn to be daring, to hope, to develop quickness of mind, and the ability to size up your opponent. These are all traits we can use throughout life. Next, you have to practice, and that means discipline. You have to get into a practice mode when you get into a sport.
Sports have to be practiced just as the piano has to be practiced.
Practice means repetition. Practicing of technique often can be fun, but in any case it's crucial to success. The idea behind practice is that eventually the skill you are aiming at comes under hand. Once you achieve a skill it becomes like a habit, second nature, and the difficulty disappears. It's much more fun to win than to lose, and people are sometimes tempted to bend the rules in order to win.