One ability is try to develop is learning from each game and match you play but then forgetting those games and matches.
Let me explain.
After you come off court after a game, you need to be able to analyze what happened, think about what you need to do to improve and what errors, mistakes and weaknesses your opponent has.
As soon as you walk on court for the next game or match you have to assume it’s the first game. Just because you won or lost the previous game easily doesn’t mean it will be the same in the next game.
Just because the opponents boast was weak in the last game doesn’t mean it will be weak this game.
You have to approach each new game with a fresh attitude.
Remember, they are going through the same process as you. When something isn’t working you have two choices; stick with it until it improves (hopefully) or change it.
I am sure you can guess what the smart players do.
Being able to move on from a 9/11 or 10/12 loss is something the better player do.
Make no assumption about each new game. Each game is a chance for you to be a different player. Be that type of player.