Writing Advice: Write What You Know

“Write what you know.” I’ve heard this attributed to Mark Twain but I’m not sure if this is accurately attributed. If you know more about who first said this, I’d love to hear from you in the comments or email me! The librarian in my is very concerned with giving attribution to the correct people! Many people get frustrated by this piece of advice. I was one of them because I’m a fantasy/sci-fi writer. How can one know about a creature that doesn’t really exist…dragons, unicorns (although maybe they are real, but really good at hiding), and trolls (these do actually appear on the internet all the time, just not in the literal form that I write.) I have a friend that writes about an ICU nurse who turns into an amateur sleuth. As far as I know, she’s never investigated an ACTUAL murder, although she was an ICU nurse. You get the idea right?