And yet, losing requires more mastery than success, as it is painful and at least as dangerous as winning*. Both are times to pay the price without paying too much.
If you are not ready to pay a price for winning and for losing, you are too weak to start taking risk in the first place.
This sounds like platitude - most proven wisdom does - but paradoxically, it is deep truth, surprising for some: a bad loser is not of the winners. So, you better learn to lose properly as a part of learning to win. It is useful to know in advance what to do when you lose.
The simple thing to keep in mind is that you do not need to perish each time you fail something. A fall is not the end of the world. The wheel will keep turning, there will be ups and downs, as long as you live. In fact, loosing some and wining some is the sign that you are still alive.
You may even take advantage from the occasions of loss; losing with grace and courage will not only ease the hurt or help you diminish de loss, but also build up your credibility and the respect of other people - that in turn is the substance of future success.
Defeat, not victory is when real quality shows. If you are strong while you lose, "If you can meet with Triumph and Disaster and treat those two impostors just the same" , people will grow confident that there is someone inside you, a person, one capable to win later.
The strong and the skilled will acknowledge, stop the part of harm that depends on them and start immediately what is needed to repair or do better, at least, not to do worse. Say “yes, I was wrong” or “yes, you are stronger”, “I am sorry, please excuse me!” Even foes respect this.
Prevent the flood, just say “Stop!, swiftly. "This does not work." "This dream was mistaken. Let us do better.” Or, don't say anything, just leave the place, now. If needed, run! Try another life; when you cannot change things out of your power, you can always change yourself.
Draw a dignified line, offer a respectful rite of passage for what was, and for the persons involved, start a new chapter.
"Good losing" is a unique occasion of learning from experience, because what you understand now you will not forget. Such learning becomes part of who you are. An educated person, competent when losing, must conclude a defeat by examining - alone or with friends - what worked and what to avoid. This is wisdom extracted for the future and precious experience to nourish the later moments when you will say: “This reminds me of...” The bad loser who neglected the work of understanding, gains nothing, only remembers humiliation, bitterness, unfinished business and hatred.
Skill in a time of loss means acknowledging, not giving up; it combines courage, humility and patience but also untiring resilience in following your deeper or higher course; like the water of Tao, temporarily evaporated into clouds, or frozen or muddied, which will lie dormant as long as needed, without sterile struggle, but which will flow at the first occasion when the way is open, it’s natural course to where it belongs .
* and thus rising envy
 Rudyard Kipling, If