Good Sportsmanship refers to virtues such as fairness, self-control, courage, and persistence, and has been associated with interpersonal concepts of treating others and being treated fairly, maintaining self-control if dealing with others, and respect for both authority and opponents.
Life is a sport, isn't it? You do not always win, but try to be a "good loser", not a "sore loser". Do not blame others for the loss, accept responsibility for your personal actions that contributed to the defeat, do not react to the loss in an immature or improper fashion, do not make excuses for the defeat, and do not cite unfavorable conditions or other petty issues as reasons for the defeat. It is easy to say but hard to do. When you are young, normally you do not take the failure well. Now I understand why it is so important to teach kids sports. It is not just build their body, but also their soul, make it more durable. When something happen later on in their life, they can hand it has a "good loser".
Bad winners, I have seen a lot, they act in a shallow way after the victory, gloating about the win, rubbing the win in the face of opponents and lowering opponent's self-esteem by constantly reminding opponent's poor performance in comparison even if the opponent competed well. In Chinese traditional education, we are always taught to be humble, even after you win. But the American culture is different, I do not mean they are "bad winners", but in a way to be proud of yourself, and have self-esteem.
If you win, be a good winner. If you lose, be a good loser. It is not a shame to lose! Be the way you are and be proud of yourself!