The purpose of delaying the revelation about Neddy's family and home is to provide a shock factor after we see all the things he was doing to deflect his reality. It is more fascinating for the reader to see a man as narcissistic as Neddy go spiraling down and acting in the way he was acting. We embark in the journey the same way he does, and we "swim" with him in every pool, we even feel a bit ashamed for him when he starts crashing parties in his swimsuit at the shocked stares of onlookers. Then, when he starts to lose his mind and fails to recognize even the constellations above him, we realize its time for him to go home. As he does, the shock factors comes in: We finally see that he had lost his home way back, possibly. We also see the shock factor on his family abandoning him and, finally, we come to the realization that this so-called "mission" was nothing but a sad case of escapism due to trauma.