The Situation and the Story
This interesting and pleasant examination of the art of personal narrative hinges on the understanding that, while in fiction our narrator may be unreliable or unlikable, in memoir he cannot.
Every work of literature has both a situation and a story. The situation is the context or circumstance, sometimes the plot; the story is the emotional experience that preoccupies the writer: the insight, the wisdom, the thing one has come to say.
This distinction is useful in thinking about writers like Orwell whose personae turn out to differ from the person one met on the street, since an unpleasant person can create a pleasant voice just as a perfectly nice novelist can write a villain.