I didn't set out to be a writer. Accidentally there comes a point where you think you have something to add; often the discourse comes from different directions.
There are authors deeply immersed in their field and craft; they continue to write in a particular vein; philosophy, history, romance, or science fiction. I find it easier to write about whatever I'm intrigued by at the moment and believe that I'm able to contribute some small different perspective.
I try to stay within the guide-rails of proper grammar, undertake an adequate amount of research and render some result in a personal voice.
In trying to write, that's the modest best we can hope for.