Apparently when Wallace Stevens won the Pulitzer Prize, one of his colleagues at the insurance firm said "What – Wally a poet?"

http://www.kevinstevens.net/writings/wallacestevens.htm

My favorite example of this is Kafka, who worked for an insurance company. Who else but someone working in a large, bureaucratic organization could have written the kind of stuff he wrote? And his work contains some of the best reflections on the nature of modern life, the fact that we're just in this huge machine and understand at most 0.00000001% of it.

Jorge Luis Borges in a book of memoirs told that when he worked in the library in Buenos Aires as a clerk one day one of his colleagues barged into his office to show him an encyclopedia (or list of famous people, or something like that) that showed another argentinian named Jorge Luis Borges, a famous writer at that, who was born on the very day that Borges was born! (of course, it was an article about himself)

Nobel prizewinner J.M. Coetzee's "Youth: Scenes from Provincial Life II" has an interesting look at his life as a computer programmer in London in the 1960s.

Non Nobel-winner Michel Houellbecq's book "Whatever" is a dark but somewhat hilarious story obviously based on his former day job as a computer programmer.

Jorge Luis Borges, a critic of the Peróns, was once promoted from his position at a municipal library in Buenos Aires to something like "Chief Poultry Inspector". He never filled the post.