‘Write what you know’ – It’s a phrase we hear a lot and while I think it’s a piece of advice worth taking in terms of being familiar with the content of your work, be that through research or planning, I must admit I’m not as convinced in terms of the more literal sense of the phrase.
You don’t have to be a serial killer to write a good novel about one, nor do you have to be a doctor for your lead character to work in a hospital. If you have ever felt restricted as to what you can write about, I would put to you that if everyone were to stick exclusively to what they knew, the world of fiction would become profoundly dull. The Lord of the Rings, Harry Potter, Game of Thrones; none of these multi-million selling franchises would even exist if their respective authors had not been willing to embrace the unknown; to push boundaries and write out with the restrictions of the real world and their everyday lives.
So, by all means do your homework and strive to make your books believable within the context of whatever genre or setting you may choose but never be afraid to set your imagination free.