This is one of those stories I would like to use more often.

Once upon a time, in a far away land, there lived a farmer with his family. This farmer had a horse that one day, ran away to the hills. So the farmer and his son had to plow their fields themselves.
Their neighbors watched them working hard and said “Oh, we pity you, what bad luck that your horse ran away!”
But the farmer replied “Good luck, bad luck, who knows?”

The next week, the horse returned to the farm, bringing a herd of wild horses with him.
“What wonderful luck!” cried the neighbors,
but the farmer responded “Good luck, bad luck, who knows?”

Then, the farmer’s son tried to ride one of the wild horses. He was thrown off and broke his leg.
“Ah, such bad luck!” sympathized the neighbors.
Once again, the farmer responded “Good luck, bad luck, who knows?”

A short time after, the emperor recruited all young men to join his army for battle.
The son, with his broken leg, was left at home.
“What good luck that your son was not forced into the army!” celebrated the neighbors.
And the farmer remarked “Good luck, bad luck, who knows?”

If you prefer to listen to his story, Sean Buvala tells a great version on YouTube.
Good luck, bad luck?