“Mistakes are the portals of discovery,” wrote James Joyce in “Ulysses”. In 1888 Lee Kum Sheung, a young cook in a coastal province in southern China, forgot the oyster soup he was boiling on the stove until it simmered down to a thick, sticky gravy. Once he discovered how tasty it was, he decided to sell his “oyster sauce” in jars. That lucky mistake would make him and his heirs rich. According to Forbes, the Lee siblings—his great-grandchildren—are worth $17.7bn, making them the fourth-richest family in Hong Kong.