Good luck bad luck – a story

A Story:

There is a Chinese story of a farmer who used an old horse to till his fields. One day, the horse escaped into the hills and when the farmer's neighbors sympathized with the old man over his bad luck, the farmer replied, "Bad luck? Good luck? Who knows?"

A week later, the horse returned with a herd of horses from the hills and this time the neighbors congratulated the farmer on his good luck. His reply was, "Good luck? Bad luck? Who knows?"

Then, when the farmer's son was attempting to tame one of the wild horses, he fell off its back and broke his leg. Everyone thought this very bad luck. Not the farmer, whose only reaction was, "Bad luck? Good luck? Who knows?"

Some weeks later, the army marched into the village and conscripted every able-bodied youth they found there. When they saw the farmer's son with his broken leg, they let him off. Now was that good luck or bad luck?
Who knows?