There is a dilemma between Robin and her external world. People like her, for the most part, but something about her relationships makes her feel claustrophobic and frantic, like they're pretending all the time or something. She wants to find something real, so sex becomes a helpful avenue for her exploration, because she can investigate how different men treat her in bed, and how she feels about them and herself.
The point of her character is to find autonomy in the midst of a kind of hybrid dependency. Although she doesn't trust anyone enough to truly feel fulfilled in her relationships, she is truly dependent, still, because she doesn't want to be alone. When the novel ends by sending her to church, it also provides a companion symbol for the church. In church, a dog falls asleep, a picture of nature at rest.
She wants to know her nature so she can rest, but without confronting the unknown, she is limited to the games of her social world, but those games have specific purposes, purposes which aren't necessarily to make someone happy. When she uses people to make herself happy, she fails, and she ends up with bitterness and regret, but when she realizes in a moment of clarity that she is existentially lonely, she finds something beyond social life that needs fixing. She needs to learn how to love herself.
