The writer's job is to tell the truth.
The good parts of a book may be only something a writer is lucky enough to overhear or it may be the wreck of his whole damn life - and one is as good as another.
Everyone behaves badly--given the chance.
There's no one thing that's true. It's all true.
Perhaps wars weren't won anymore. Maybe they went on forever. Maybe it was another Hundred Years' War.
What a writer has to do is write what hasn't been written before or beat dead men at what they have done.