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.
Bukowski: pickle factory for a while then 13ish years at the united states postal service
Anthony Trollope worked at the post office, Andy Weir was a programmer until he hit it big with The Martian.
Wilfred Owen: soldier and poet (whose poetry was ignored/neglected until the 1960s)
TIL Kafka worked in insurance... wild!
This is messing with my head. I love Spinoza and Kafka and couldn't imagine them as anything else but being full-time thinkers and writers.