When I was 15 (Sophomore year) I was an atypical small, skinny, quiet, thoughtful high school football player without a lot of self-confidence. I went away to a week long summer football camp at Michigan State University. I wish I had the essay I wrote on that experience to publish here. The main coach was the MSU football team strength training coach (the guy who you picture screaming down into your face while you grunt and sweat and struggle for all you're worth to put up the bench press rack you're trying desperately to keep from falling back down on your throat and thereby cutting off circulation, air flow and ending your stint in this game). The kind of guy you're surprised when it turns out he's able to speak in complete sentences.
I learned to let go of the things I wasn't able to control and focus on the ones I was. The weather, the other team, the field surface, the referees, these things are traps your mind can get stuck on. You have no influence on them whatsoever. You simply release them. Your own play, your preparedness, your diet the day of the game, your mental state - you take ownership of these things. It was a good lesson.
I learned to be tough. Mental toughness is so much more important than physical toughness. I've never been in a fight in my life (one that wasn't consensual anyway). It's extremely unlikely that in the course of my day I would have an actual physical altercation with anyone. Why would I be afraid or intimidated in any interaction? Why would I let anyone force me into doing things that aren't who I am?
I feel that I can hold my ground intellectually with anyone I meet - and if they know more than me in some arena, I smother them with questions and systematically extract their knowledge to make it my own. Toughness is approaching life as if you feel comfortable in it. If you can learn this through running 50 yards full speed and throwing your body against someone else's, falling down and standing up to do it again, great; there are probably other paths to this knowledge as well.
Toughness is often admitting your limitations and being able to see yourself as something larger than your skills, abilities, strengths, weaknesses. Seeing yourself as malleable. Feeling that you need to cover up a weakness means you'll never get past it. Sometimes strength comes in exposing weakness to the daylight and asking what you need to do to get past it. Having confidence in yourself that you can figure it out. Knowing that everyone else is just as sorry as you are and that if you can admit it you're 100 times better off that they are. On a similar note, I often think of things I'm doing - even things I've been doing for years - as experiments, as things I'm able to watch and make decisions about and try out or walk away from if they're not working out for me.
In football, you learn to force yourself to do things that are hard. That no one should really have any good reason to be doing. There was one summer we were doing a pre-season training where we ran up a giant hill 8 times in a row. No one was in shape - this was early enough in the season before it was allowed to start training with pads or anything. So we were just running. It was hard. After the 4th or 5th ascent, I stumbled off into the trees and puked. I felt like I was going to die. Then, after releasing it, I felt better. I went back and finished the workout. You don't learn that playing video games or reading books.
When you have this - which I think is willpower - there is less of a divide between thought and action, which I think is helpful in the new-years-resolution kind of things where people say "This is what I should do" and then fall back into old habits. You just do it. That's all there is. Nothing happens in life but that someone - an individual - does it. It's great. I tend to view things in systems. If something is a rule, it's a rule, you do it. There isn't much rationalizing. I think this would make me an excellent member of the armed forces. Of course, I get to vet all the rules.
I'm a little surprised at how down on football people are. Those people are assholes. You can learn from anything if you pay attention to it. You heard it here first.