Let me explain: I write fiction, and I do read it and have my favorite authors (among them Isaac Asimov, Spider Robinson, Elmore Leonard and Mark Twain) but while I’m writing I don’t read other fiction.
The reasons are many. First off are to avoid plagiarism. When I’m trying to keep my own voice in all my fiction, make sure that all of my plot twists are of my own devising, I want to ensure that nothing in my prose has come from someone else’s work.
When you start to write, you copy from your influences… I still have some in my own work that hearken back to Spider — but the chosen words and fiction itself is purely my own.
Another reason that I don’t read other fiction while I write is that influence. I built others into my ‘voice’ when I write, but this comes from reading them for years. If it came from reading them now, that would really mess me up.
So, right now I’m reading non-fiction — but when I write non-fiction, I’ll only read fiction, for the same reasons.
There is a negative side to this: it’s been about 2 years since I began to write my current novel, which means that I haven’t read any other novels in that time.