Anne Lamott (Bird by Bird: Knopf Doubleday Publishing Group, 1995) talks about "life being a recycling centre." It's true, isn't it? Everything has happened before.
Don't you love it when suddenly you recognize your own life in something you are reading? You know exactly what the author is saying. He's been there, done that.
That's something we writers should strive for -- that ability, as Lamott calls it, "to turn on the light for the reader."