Epigraphs are like little appetizers to the great entrée of a story. They illuminate important aspects of the story, and they get us headed in the right direction.
What is your original face, before your mother and father were born?
- Zen koan
The epigraph touches on a central theme of Please Ignore Vera Dietz, which is how much we are impacted by who our parents are. Charlie and Vera are both haunted by the idea that they'll end up like their parents; he worries that he'll become an abusive tyrant like his father, and she worries that she'll turn out like her ex-stripper mother or become an alcoholic like her father.
In the end, Charlie goes down the wrong path and does hit Vera (just as he always feared he would), and Vera starts to drink too much like her father. But she's able to pull herself out of it and make the right decisions for herself by the completion of the book, revealing to the reader that her fate isn't fully dictated by who her parents are. She finds, if you will, her original face.