In 1754, a belle-lettrist named Horace Walpole retreated to a desk in his gaudy castle in Twickenham, in southwest London, and penned a letter. Walpole had been entranced by a Persian fairy tale about three princes from the Isle of Serendip who possess superpowers of observation. In his letter, Walpole suggested that this old tale contained a crucial idea about human genius: “As their highnesses travelled, they were always making discoveries, by accident and sagacity, of things which they were not in quest of.” And he proposed a new word — “serendipity” — to describe this princely talent for detective work. At its birth, serendipity meant a skill rather than a random stroke of good fortune.