Other examples: Baruch Spinoza, lensmaker by day, philosopher by night. Philip Glass: moving man, plumber, cab driver, and avant-garde composer. E. E. "Doc" Smith: food engineer and science fiction writer. Franz Kafka: administrator in an insurance company, and writer of history's weirdest books. Wallace Stevens: insurance company executive and poet. William Carlos Williams: doctor and poet. And these are just off the top of my head.