Sensible advice. Controversial advice. I’ve heard it pronounced worst writing advice ever, but I disagree. Notice it doesn’t say “write what you have first-hand experience with.”
I’m all for first-hand experience, which is why I am dying to take a gun safety glass and shoot a few rounds. Until I have the opportunity to do that, though, I’m just going to spend more time at the library, reading up on handguns, thumbing through magazines for police officers or other security personnel. I photocopy articles and ads. I jot down website addresses and read those “it happened to me last week” anecdotes (almost as good as interviewing someone).
“Write what you know” doesn’t mean I have to own an M9 and shoot it regularly; it means “do your research until you know the subject you are writing about.”
While some writers might think so, “write what you know” does not limit you to write about characters with professions you’ve worked in, living in cities you’ve seen, doing things you’ve done.
The truth is, I rarely write about stuff I “know.” But I make damn sure I know what I write about.