The damage of divorce
It is painfully ironic to be a child whose father has abandoned the family. The difficulties of romantic connection are obscured by the dramatic irony of innocence in the children's perception. For instance, Cody and Ruth each have several intimate relationships in a quick succession; that proves that intimacy is extremely challenging, but they still have to experience their parents' divorce as if it is a reflection on them. It is not a reflection on them; it is a reflection of a bad marriage. Ironically, the children cannot tell the difference.
Approval and self-worth
The children grow up and become interested in making families, but they fail because each person is extremely broken from their childhood. The only person who has managed true love is Ezra, and Cody cannot handle it. He wants Ezra to fail like him. This is evidence of an ironic relationship to self-esteem. Although the children are not guilty for their parents' divorce, they internalize the divorce as a measure of their self-worth, and then the approval of admired romantic partners becomes like a fuel or an addiction to help them function.
The competition of brothers
Empathy seems like an obvious option to the reader. After all, two brothers enduring the same family dynamic means they have so much in common. Why would that struggle not bring them together? The answer is that it might bring them together eventually, but as the novel demonstrates, they must first navigate the ironic competition that limited family health brings about. When approval and self-esteem become limited resources, it becomes natural for siblings to compete against one another. This is ironic because it just makes more problems, but it is a natural problem.
The unhealthy healthcare worker
Ruth becomes a pediatrician, but her private life is defined by emotional dysfunction and confusion. Her marriages are proof that she cannot quite figure out how to be in a trusting relationship. It is as if she keeps finding reasons to doubt her marriages—which is exactly the outcome that might happen if her father left her mother. Her focus on health and wellness is an ironic note of contrast that illustrates what might perhaps be diagnosed as a kind of PTSD.
The dinner
The story has a central aim or goal that defines the whole landscape of the novel: to have one family dinner. What might be commonplace and ordinary in a healthy family, eating around a table, has become the object of mythic sacredness to these young adults. Just to get their parents to share the table is a nightmare and a half, and then once everyone arrives, they have to wade through the emotionally heated and painful waters of conflict and fighting. By the end, they manage to have one, just one, family dinner. This fact shows the depth of dysfunction.
