Different people will respond to this question in different ways as any work of literature will strike individuals in different ways. Another interesting element is that this is a depressing book, overall, so to find a "favorite part" is a challenge. I think that the detailing of a disintegration of a friendship is one of the most thought- provoking elements of the novel. Anderson shows the friendship between Cassie and Lia as one that has endured quite a bit in terms of challenging situations and the construction of shared memories. Yet, the way in which their friendship ultimately becomes a sacrificial element to the self- destructive and socially driven element of bulimia and anorexia. The fact that both conditions are both psychological and sociological reflects some of the basic challenges that exist in any adolescent friendship. The reclamation that is often shown is not present in this context. I think that this becomes one of the thought provoking elements of the novel for it shows the reality that governs modern adolescent friendships. In this, the fact becomes that not all of them survive the challenges that are present, causing one to reflect about their own associations and how they would stand up to such challenges on psychological and sociological grounds.