Quotations and aphorisms by Diane Johnson:
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.
But 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.