“Novels are never about what they are about; that is, there is always deeper, or more general, significance. The author may not be aware of this till she is pretty far along with it. A novel’s whole pattern is rarely apparent at the outset of writing, or even at the end; that is when the writer finds out what a novel is about, and the job becomes one of understanding and deepening or sharpening what is already written. That is finding the theme.”–Diane Johnson
Very much agree with that. I don’t think many writers sit down to write about a particular theme and end up with a compelling story. Themes have to emerge naturally and with layers of complication.
(H/T Advice to Writers)