There is a very old folktale that dates back to the Sassanid Empire about the Three Princes of Serendip, who travelled the world, making discoveries. These seemed to be accidental, but the discoveries were reinforced by the princes’ wisdom in recognising and taking advantage of these apparent accidents. During the 18th century the art historian and antiquarian Horace Walpole brought the word “serendipity” into the English language based on this story, in which the heroes were “always making ...