I learned in childhood that competition can sap all the joy out of sport. It's a lesson to be heeded at all stages of life.
I enjoyed playing baseball in pick-up games around our neighborhood but dreaded playing it in Little League where adults yelled at small boys for ordinary play. I remember standing on the field hoping the ball wasn't hit to me for fear of making an error and becoming a target of abuse from adult coaches.
There's intrinsic fun in all physical activity but you can ruin a good time by focusing on "winning." True winning is enjoying yourself. If you're not a paid professional (as none of us are) fun should the goal, not beating others in matches that don't matter. That's my attitude in billiards, motorcycle-riding and other activities.
I also use this insight as a spectator. Competition is okay to keep score of how your team is doing but shouldn't obscure the magic of their play. This year I went to ten hockey games. My team (NJ Devils) is one of the very worst in the NHL. Overall they lost more than two out of every three games they played -- yet I loved the excitement of attending. I saw young players developing promising careers, an old player savoring his remaining time on the ice, crowds roaring with delight at spirited play and a community wearing colorful jerseys to share their pride. Those games were highlights of my year and unaffected by whether the team won or lost. (In fact, they won seven of the ten games.)
We can choose how we live and think. Much modern culture, especially around sports, is wrong-headed and leads to unhealthy experience. Adopt the right attitude and sports can enhance your life.