What is the importance of the "island near the city" in the novel, Very Recent History?

In an extended section of text at the end of Part 1, protagonist John spends part of his short vacation on an island near the City. Because of several references to real-world places and situations, this island can clearly be seen as Fire Island which, for decades, has been the setting for promiscuous male homosexual partying. As a result of his experiences on this particular island, John experiences important discoveries about how he feels about the life he has been living.