The money quote:
And so I found myself torn: I wanted him to pass, I wanted those instructors to see that he's only five and he tried his best and give him that belt. He's five; there will be plenty of opportunities for him to have his heart broken.And at the same time, I wanted him to fail. I wanted him to know that he needs to work for things, to understand that very little in life is given to you, to know that the hardest earned victory is the sweetest. All those cliches that your high school gym teachers taught you, I wanted him to learn.
How does it end? No spoilers here, but there's some talk about Yoda. The whole story is worth a read.