Losing is not easily forgotten, especially if it is something that you have worked hard for, expected or been passionate about. Many people are in a competitive mood and can only forget a loss by winning. The size of the loss is also important here. If it's a small loss, it won't take time to forget it, but if it's a big loss, it will take time to forget it.
If you only heal by winning, it can put you in a fragile cycle. When you win you are on top, when you lose you fall apart. This cycle cannot be sustained. So sometimes befriending the loss, taking the lesson in it instead of immediately erasing it, makes you more resilient. And that increases the joy of winning.