Essentially, when Erica is gone, the last emotional connection between Changez and America goes with it. In a way, her absence cuts him free. Changez perceived Erica as his first love, certainly his first American love. With her gone, it enabled his break with America to be clearer and more distinct. Change's decision to return to Pakistan is made fundamentally more easy with Erica being gone. At this point, there really is nothing keeping him in America. There are no emotional attachments. With his new found perception of America as one that does not hold a place for him, the resignation of his job at Underwood Samson, and an emotional reality in which there is a lack of connection all makes it easy for him to leave America. There is nothing there for Changez. It is at this point where his departure is easy to facilitate. Changes notes this by noting to the American his lack of affect about leaving. It was as if Erica was the last vestige of hope that Changez could establish some type of home in America. Just as she leaves, he realizes that he needs to, as well. In this, his decision to leave for Pakistan is nearly confirmed wth her absence.