Can fiction ever be entirely fictional?

Victoria Patterson, author of Drift, wrote in a recent article about autobiographical fiction for The Millions that her writing group would call her by the name of her protagonist, despite her assertions that her character was fictional — and that she endured a "condemning two- to three-month silence" from her family after her book was published.

One of the most interesting things about Patterson's article is a conversation she had with her father, who brought up an event that he said he...