You hear it all the time at writer’s workshops: write what you know.
I don’t believe a word of it. Writing about what you know about seems to me a recipe for repetition and stagnation.
Instead, write what you want to know. The best writers are inherently curious, always seeking—through reading or travel or whatever—to learn something new. You could call it research. And those new things, whether sought out deliberately or stumbled upon by serendipity, often find their way into a story, a song, a poem, or a book—usually after considerably more research and curiosity.
Now, this is not to say you shouldn’t develop some mastery of the subject—know it, in other words—before you write about it. For one thing, readers who do know can spot a phony from afar. For another, writers owe readers a heaping helping of honesty, truth, and reality along with entertainment. And that’s true whether you’re writing fiction or nonfiction, poetry or plays, essays or songs, movies or magazine articles.
Texas poet Larry D. Thomas would never have imagined The Goatherd had he not been curious about what life might have been like for a man who tended goats in long-ago Texas. Michael Zimmer would not have written the outstanding novel Beneath a Hunter’s Moon had he not wondered about the somewhat obscure Métis and their ways. We would not have South Pass had Will Bagley not set out to discover the finer points of exploration and emigrant travel over the Continental Divide’s easiest crossing. And so on.
Don’t let your writing be limited by the limits of your knowledge by believing the lie that you should write what you know. Learn something new. Then, you’ll come to know what you write—and so will your readers.