There is a well-known parable in the book Master of Huainan that encapsulates Daoist's idea of the relativity of luck in life. It's known as The old man lost his horse, how could he know if this is not fortuitous (Original: 塞翁失馬，焉知非福).
Here's the story:
Once Upon a time, a skilled equestrian lived near the border. For no reason, his horse ran off into the barbarian kingdoms. Everyone felt bad for him. But his father said, "Don't be glum. Who's to say this won't take a turn for the better?"
Months passed. His horse came back with a herd of well-bred barbarian horses. People congratulated him. His father said, "Don't be overjoyed. Who's to say this won't take a turn for the worse?"
Now with an abundance of horses, the son indulged in riding. One day, he fell and broke his leg. Again, people sympathized with him. Yet his father said, "My son, who's to say this won't take a turn for the better?"
A year later, the barbarian breached through the border. All able-bodied men were conscripted to fight. Nine out of ten were killed. Due to his injury, the father and son were spared.
Thus, misfortune can bring fortune, and fortune can lead to misfortune. This happens time and time again. The evolution of fortune is endless and unfathomable.
Here's to the horse we lost this night.
Reference:
[1]: See original text here.