The discovery of someone's secret life, a second existence hidden from the world, is always of interest. It reminds me of Dr. Jekyll's second self, Hyde, allowed to act out the forbidden desires of the respectable Victorian doctor in Stevenson's novella. It suggests the possibility that each of us has, at least potentially, a double, a dark side, or a desired "other."
Reading recently about Robert Sterling Clark, who amassed the great collection of art on view in the Clark Institute at Williamstown, MA, I learned about the existence of his other life. It was not, like his father's, a gay lifestyle in Paris while simultaneously supporting his family in America: that would be almost predictable, even a hundred years ago.
Rather, Sterling Clark (1877-1956), who looks properly stern in his formal portrait in the Clark, had a secret desire to be an auto mechanic, and, unknown to nearly everyone, he fulfilled this fantasy role. His chauffeur would drop him off certain mornings at the corner near a garage, where he was known as Joe. There, free from family squabbles over money, which came from the Singer sewing machine fortune, "Joe" could happily work on cars, change clothes, and return, as Sterling, to the family mansion at the end of the day, like a successful Walter Mitty.
Leading one life is usually enough for most us; managing two, as some men do with mistresses in various locales, would seem impossible. Yet I suspect it's more common than we think.
If I were a novelist, I would be tempted to borrow the story of Clark's other life for a book about the secret lives many people live--or would like to live. Writers are lucky: they can live multiple lives imaginatively, without the bother and expense.