Okay, I know you've all heard that one before.
I guess how you react to it will depend on who you are. If you're one of those people who sailed single-handedly around the world at age fourteen, volunteered to go abroad and build orphanages for the under-privileged in Borneo at fifteen, climbed Mount Kilimanjaro when you were sixteen - and blogged about it all - you're making a smug face right now.
But if you're like me, a fairly normal person who's had a few interesting experiences but has generally lived an average sort of life, you're feeling a leeettle annoyed that someone's brought that old chestnut up again. And you kind of hate the adventurous people making disgusting smug faces right now (don't worry, so do I. Just a bit). But hang on just a minute there, Smuggy McSmuggerson! Read on, and you might find that you need to think again before writing your epic story about the smug mountain climbing kid from Ohio!
I'm going to let you in on a secret. Write what you know is the most widely misinterpreted piece of writing advice EVER. It does not mean what most of the people repeating it think it means. And that includes your teacher, your mum, and most probably that guy on the writing forum who laughed at your story about vampire unicorns. Trust me.
How do I know? Well, look at me, kids. Do I seem like a girl whose three brothers were turned into swans and who swore an oath of silence while weaving nettle shirts in order to save them? Do I seem like the kind of person who can take on three murderous mercenaries simultaneously and whip them into a souffle without breaking a sweat? Er...no. I only have one brother, and he works in a doctor's office in Sheffield, quite happily, without any untoward avian illnesses. And if I tried to pick up a sword and defend my one true love with it, I'm fairly sure I would disembowel myself.
But did I write from the point of view of people who were going through those experiences - and I got published anyway. So did I break the Write what you know rule? No, actually. Because the true meaning of this saying isn't that if you're a fifty year old dentist in Scunthorpe you're only allowed to write about other middle-aged Scunthorpian tooth-tenders. It means that what your character feels, you, the writer MUST FEEL TOO.
It doesn't matter if you're writing about three headed Smargle-Lizards from the far off planet of Squink. It doesn't matter if you're writing about a child soldier fighting for her life in Uganda. It doesn't matter if you're writing about a young person very much like yourself, going through the same things in life you are right now. What makes the reader care about your story is that they can identify with your character. Readers want to be touched. If the Smargle-Lizard is weeping over the grave of her dead mother, your reader wants to feel her pain, understand her grief. If you can achieve that, they won't care about her three heads anymore. All they'll want to know is if she's going to be all right. But if they can't feel the character's emotions and understand why she feels the way she does, they won't care if the character is exactly the same as them. The story simply won't matter to them. They'll close the book and move on.
But here's the great thing: just as a reader whose mother is alive and well can feel the grief of a character whose mother has just died, SO CAN YOU. It's not easy - in fact, it's the hardest thing a writer ever has to do. But we all have grief inside us, sadness, worry, as well as laughter, love and joy. When you put a character through an ordeal, you have to be willing to reach down into the deepest and darkest bits of your own soul and pull those emotions out. You have to live them along with your character.
If you can do that - if you find yourself laughing at your character's jokes, crying when she does, feeling joy when she does, then the reader will too. At that point you will have fulfilled the command to Write what you know in the best and the only way that really matters. Like the saying goes, if there are no tears in the author, there will be none in the reader either.
Write what you know means write from the heart. It means be brave enough to let yourself grieve and laugh and fall in love, for the world to see, right there on the page, even if you're doing it inside the character of a three-headed Squinkian Smargle-Lizard. It means, be true to yourself and your characters.
Do that? And you'll be a writer.