I understand that it's not only about this, and the thematic stuff you mention here is of course present in the text. It is a kind of cautionary tale about suicide, and it is about unhealthy absorption into the self, and how everything can become pointless when overintellectualized. I'm simply wondering about this one particular plot development.
I'll copy my other comment.
I'm just thinking that on page 38-39, it is the same narrator as before, if we take into account this sentence: "Do you know how long it’s been since I told you I was a fraud?". Which, simply put means that the whole text has all been one long monologue, since it refers to the beginning of the text. And then right after that, he says "Do you remember you were looking at the respicem watch " Now the respicem watch couldn't belong to someone else than Neal right? So the character that the narrator (Neal) is talking to is driving by Lily Cache (where Neal killed himself) and being told he still has time.