“Write what you know.”
I have heard many authors say this, when watching their interviews. This is a very good point and excellent advice for us aspiring writers. Even when writing fiction and creating our own universes, those universes have to be filled with something – and that is when “what you know” comes handy. At the beginning, it is easier to write from knowledge than going through lots of research and deep waters. It is good practice and it comes from you. If you have a background in law, you will probably apply your knowledge in that mystery or crime novel, and so on …
That doesn’t mean that we will be writing what we know forever; at one point or another, we will embark towards unknown seas and shake our confidence a bit. It just means that it is easier to write about something that will flow naturally to us and keep us going. Eventually, we all know when it is time to cross that bridge.