Truth in Fiction

Why do people read fiction? The most common answer I get (I ask this in class) is for entertainment or escape. But after that, people often answer that they are looking for the truth about the world - not necessarily their world, but a truth. Maybe it's a truth that they want to hear, as in crime fiction where the villain is always caught (and if he/she's not, the reader feels cheated!), or romance fiction where the girl always ends up with the hero who turns out to be perfect for her.
Books that tell the truth too clearly are often the ones that cause a stir and end up being widely acclaimed. I'm thinking of "We Need to Talk About Kevin", in which we have a mother's burning need to be totally honest about her son's life, and her relationship with him, in order to try and figure out why he became a mass murderer. It's a scary book, and I wonder how many people saw their own relationships reflected in the story, even if only in small ways.
How do we write something "true" when we are writing fiction? I still believe you have to write from what you feel deeply about, even though I know lots of people who don't, and are published. But maybe the books that make a mark in a reader's life come from somewhere else in the writer. Something that has to be expressed, a story that has to be told. Will Charles Frazier ever write something as good as "Cold Mountain"? Lionel Shriver wrote and published many novels before "Kevin". I think back over books I've read that had an impact on me, and very often that author has written others, but there is that one book that stands above the others.
Where does that book come from?
Another aspect of this is the need to produce, of course. A first novel can take years to write and rewrite, and it has to be really good to get published (the first-time author is, I believe, the marketing department's nightmare!). But then there is pressure to write another, and another. The next books don't receive the same care and incubation a lot of the time. Sue Grafton wrote a stinker half-way through her alphabet crime series, and she was able to say to the publisher, "Enough. I will write at my own speed from now on, thank you." (not a direct quote!)
One book does not earn you enough to quit your job and devote your life to writing, unless you like bread and water. That's another truth about fiction.
Note: The Varuna fellowships are announced today. This is the scheme where writers submit fiction manuscripts and five are selected by HarperCollins editors for an intensive 10-day workshop up in the Blue Mountains. This year, the editors received a shortlist of 26 manuscripts, and I bet most of them are publishable. However, Australia's literary fiction scene is getting smaller and smaller, and all of those writers not in the 5 will have to call on every ounce of that vital quality - perserverance - to keep going with their books.
That's another bit of truth in fiction!