My dad used to tell me a story similar to this one, but I couldn’t find the same version. The lesson is the same though and one I try to remind myself of often

The Horse

Once upon a time in a village in ancient China there was an old man who lived alone with his son. They were very poor. They had just a small plot of land outside the village to grow rice and vegetables and a rude hut to live in. But they also had a good mare. It was the son’s pride and joy, and their only possession of value.

        One day the mare ran away.

        The old man’s friends came to him and commiserated. “What a wonderful mare that was!” they said. “What bad fortune that she ran off!”

        “Who can tell?” the old man said.

        Two weeks later the mare returned accompanied by a fine barbarian stallion. Friends and neighbors all came around and congratulated the old man. “Now you have your mare back, and that stallion is as fine as any in the land. What a stroke of good fortune!”

        “Who can tell?” the old man said.

        Two weeks later the son fell off the stallion while riding and broke his leg. Friends of the old man came to him to express their sympathy. “It’s too bad your son broke his leg, and right before the planting season, too. What bad luck!”

        “Who can tell?” the old man said.

        Two weeks later, war came to the land, and all able-bodied young men were drafted. The troop that contained the men from the village was at the front in a bloody engagement, and the entire troop was lost. All the men from the village died in battle.

        The young man with the broken leg stayed home. His leg healed. He and his father bred many fine horses, and tended their fields.

(Huai Nan Tzu)