There are many great examples of serendipity throughout history - the discovery of penicillin and the inventions of the microwave oven and the Post-it note get a mention on Wikipedia.
How about in your life?
Serendipity traditionally means discovering something good without looking for it.
I find in reality that the more I look for what else is, might be or could be in circumstances and situations the more I discover.
I find this particularly so when I look for the good, the great and the remarkable in situations where there's conflict, difficulty or disagreement.
When things don't go according to plan asking What if?, What else and What can be? are great questions to ask.
Who will you become?
What will you do next?
"The real voyage of discovery consists not in seeking new landscapes but in having new eyes."