One important memory that Will has about his mom has to do with her and Erleen. Specifically, the memory involves what happened to Erleen during a shopping trip. Erleen is accused of stealing. Erleen maintains her innocence, and Will’s mom appears to take her side even though Will seems to imply that Erleen was, indeed, shoplifting.
The memory seems to have taught Will about the importance of friendship and loyalty. You might argue that the memory of Rose and Erleen’s friendship informs Will’s relationship with Harlen. As with Erleen, Harlen doesn’t always act with the greatest amount of forbearance or consideration. Yet despite his somewhat annoying tendencies, Will sticks by him.
As for James, you might want to discuss how Will’s memories of his brother help make him a complicated person. As a grown-up, Will comes off as mostly good and honorable. His integrity is reinforced by his attentiveness to Susan and Louise. Yet Will’s memories of James demonstrate that Will was not always such a good person. Will has engaged in bad behavior, like when he, James, and another boy played a mean trick on a girl with a developmental disability.
As for memories of his dad, you might want to think about how Will’s lack of personal memories of his father inform his personal growth and life in general.