There's a passage in the Daily Stoic that stuck with me in describing how stoics stayed, well, stoic. I forget the exact quote, but the idea was that stoics were always striving to strike a balance between being the scholar, and being the soldier. Which simply means, they understood the importance of working and improving both their intelligence (scholar) and their physical capacity (soldier), not one or the other. For me sports offers this opportunity to be both the scholar and the soldier or how I like to see it, the nerd and the athlete. As long as one has an open mind, is striving to constantly learn, and is curious, sports create an amazing environment in which a person can learn the beauties of life and learn about how their body and mind functions under certain stressors and circumstances.

So to answer your question, sports can be an all encompassing activity that can teach most of what you need to know about life. But often, we only see the physical side of sports and waste the potential that is there to use it to enhance our intelligence (think jocks, super athletic but not the brightest). Thus, the most important lesson kids and adults alike can learn from sports is to strive to be nerdy AND athletic! And stay curious!