Several lessons come through on every show.
1.) Hard work is the key to success
I love that the show spends a significant amount of time focused on training. Most teen boys only see the glory of playing before packed stadiums. Hard Knocks shows the wind sprints, weight lifting, and practice drills.
2.) Not everyone gets a ribbon
Our schools, our communities, and parents-at-large have done a very good job at deflating the ugliness of competition. I'm all for inclusiveness, building self-esteem, and lowering the intensity of crazed youth sports' coaches.
But, many teen boys do not seem to understand that they can't simply "sign up" to make the team or get into college or get a job. Seeing top athletes cut from the team illustrates the reality of the world.
3.) Dealing with criticism is part of becoming a man
Watching the coaches chew out players (again - language warning!) is great for several reasons. First, you'll have a shared laugh. Some of the insults and the lectures are unintentionally funny. Second, your teen boy will see how men learn to deal with criticism and third, you'll look far nicer in comparison!