For our anniversary, [Amy] always set up an elaborate treasure hunt, with each clue leading to the hiding place of the next clue until I reached the end, and my present. It was what her dad always did for her mom on their anniversary, and don't think I don't see the gender roles here, that I don't get the hint. But I did not grow up in Amy's household. I grew up in mine, and the last present I remember my dad giving my mom was an iron, set on the kitchen counter, no wrapping paper. (3.26)
When people get married, they bring all kinds of baggage into the relationship, including what their own parents' relationships taught them about marriage. Amy seems to have unrealistic expectations of what a long-term relationship is like, probably because her parents have a bond that couples rarely maintain after twenty-five years of marriage. Nick, as the child of divorced parents and an abusive father, has seen something far different.
And the moral of the story is this: Nick and Amy's very different past experiences create expectations on Amy's part that are impossible for Nick to fulfill.