塞翁失马
"It can be difficult to foresee the twists and turns which compel misfortune to beget fortune. There once was a man who lived near the frontier with his son. One of his horses accidentally strayed into the lands of the Xiongnu. Everyone consoled him, but the man said, Why should I hastily conclude that this is misfortune? Months later, the horse came back with another stallion. Everyone congratulated him. The man said, Why should I conclude that this is good fortune? One day his son fell off a horse and broke his leg. Everyone consoled him,but he said, Why should I conclude that this is misfortune? One year later, enemies invaded the frontier, and all the men went to war. Of those who volunteered, 9 out of 10 perished. It was only because of the son's broken leg, that man and his son were spared. Misfortune begets fortune, and fortune begets misfortune. This goes on without end, and its depths can not be measured."