Competing is getting to training early and warming up on your own. It is about not stopping your movement until the coach calls for rest. It's about going to hit all the balls in practice, including the ones that miss the line, because you know that if you continue to hit them, you can hit them all in the game.
Competing means giving your 100% regardless of the player in front of you. Does your opponent play worse than you? Make sure you don't make mistakes and that he always fails. What other opponent is better than yourself? Make sure you move your legs as much as possible and be extra careful not to make mistakes.
Competing is respecting your coaches, asking them your doubts and insisting on pointing out any weakness in your game. Competing is collecting balls quickly to make the most of the time. It's feeding your body like an athlete and putting aside the cans of Coke and the boxes sweets you love so much.
It's stretching after every training/game without your coach having to remind you. It is analysing the game, and training while looking for what to improve. It's making sure all of your racquets are strung and with the grip in place for every workout.
It's watching and analysing matches of top players with similar characteristics to see how you can look like them. Competing is ending the day thinking if what you did on the field today was enough to make you improve. Competition is not just about playing tournaments and earning points to go on top of a leaderboard, it's just part of the growth.
You truly become a "competitor" when you care about everything that surrounds your sport and do things convinced that your efforts, on and off the field, will transform you into the best version of yourself. So, when defeat occurs and you cry with anger, ask yourself if you are really doing everything to be better than the one in front of you.
If the answer is yes, then don't stop insisting because over time you will reap the rewards of your effort, but if the answer is no, then don't come with your tears, as you clearly don't have the mentality of a winner.