The surprise was the story about the cows which wasn't in the original draft. I included it later. The subject matter, though, tapped into a lifetime of thought and concern. Semitism is a constant theme in my work. Mostly, I write fiction.
Fiction speaks from inside invented characters who are telling their story or stories.
Yet, I approach the writing of both fiction and nonfiction in the same way. In both fiction and nonfiction, I go back to my journals and skim, looking for entries that tap into the same subject matter. I read and I think. Often, I'll read other writers. If I need to, I'll do research.