Write what you know. That is an advice often given to writers, especially the ones who start their first journey into the realms of words, paragraphs and pages, lots of pages.
It is sound advice, because when you write about what you know, you can be fairly certain that you don’t make a silly one of yourself (and I deliberately avoid the word ‘fool’ here since anyone who is brave enough to set out on the lonely path of the writer is not a fool in my opinion).
So there you are, a beginning writer, writing what you know. You know a lot about cars, so you could write about cars. But you know perhaps a;sp about the solar system, so you can employ that in a wonderful piece of science fiction. After all, there is enough material online and in libraries to research rockets and such to make the story credible, and a rocket – like a car – is merely a means of transport, be it a big and expensive one.
And then, amazement, the book is done and you feel like more writing, more science fiction, more rocket-cars, so you dive into your keyboard again or perhaps your preferred notepad and fountain pen, and off you go into the wonderful world of Scifi, with rockets and stars, and – oh… perhaps there is something about these astronauts that you can elaborate on. Some psychological things that might affect them when they fly along and barely make it past a supernova alive. After all, astronauts are human too. But you know nothing about psychology. So should you stop here, because of that advice that you should only write what you know?
No. Absolutely not. Because look at what you did when you wrote that first book. You ran to your favourite library or search engine and you looked up rockets. You can do that for matters of the human psyche as well, even though that is a slightly different grey matter than a rocket. It might be just as big, though.
You can also look around in your neighbourhood and see if there are people who know something about psychology; people you can talk to and who might want to help you figure out the bits and bobs that go around behind an astronaut’s forehead.
You can try to locate online forums where psychology students get together and discuss things with them. And behold, when you do that you are learning about psychology. You start to know things about it. And then you are where you want to be: you write what you know. Congratulations, you just expanded your writing horizon by learning something new!
So the message is still: write what you know. But if you don’t know something, get to know it.