Nobody likes losing. (If you do, Dumb Ways to Lose might help.) There are always those players who smile immediately after losing, but usually that's either hiding an inferno on the inside, or it was against a much stronger player where they simply enjoyed the opportunity.
The reality is that losing a match that you could have won is frustrating. It takes time to get over a loss. Some recover quickly, others mope on it all day or week. The further reality is that if you don't get over it, it will affect you in future matches.
So, what should you do after a bad loss? There's a simple one-two combo.
- Sit down and think over why you lost. Was it a technique that needs more work? Tactical? Physical? Sports psychology? Whatever it was, figure out what you need to do to do better next time. As soon as you've figured this out, go directly to part 2.
- Five-Minute Rule. Within five minutes of losing, you have to be over it so that your mind is completely clear and ready to go again. You can time those five minutes starting either from when the match ended or after you finished your analysis in part 1. How you do this is up to you. Some just sit back and clear their mind. Others listen to music. Still others talk to others to get their mind off the match. Whatever works for you.