I was on a field hockey team when I was in high school. We lost almost all our games that year (I was a sophomore). One game we were ahead, but in the last 60 seconds, the other team scored twice. I was not on the field and slammed down my stick against the ground and swore under my breath. But it was obvious to anyone that I was angry and upset.
The head of the girls' athletic program was at the game; she also was a gym teacher. She came over to me and reamed me out for the lack of sportsmanship and crude behavior. She said I was a representative of our school and this display of anger was not appropriate. I was steamed at her, of course, for telling me how I was supposed to behave. I did take in what she said though, and over the years of playing sports and life, I have used this lesson of self-control and positive attitude even when losing.
I had her as my teacher in a weight training class later when I was a senior. I didn't really like her much, but in this class I learned 'self discipline'. I was able to set goals in the class and achieve them. She was gruff-looking and many girls didn't like her, but she helped me get an award my senior year as an 'All Around Athlete'. I guess I showed I had taken her lessons to heart.