It's a story that seeks to describe the great divide between the middle and the upper classes.
I'm really not clear what you mean by "something is about to be said...but isn't."
It's a novel. Do you mean that you didn't understand the purpose of certain story events or do you literally mean that nothing is revealed in the story.
It is hard to face such things (e.g. the realization that you no longer value the things you'd built a self around) and harder to write about them, especially if you're a talented writer and a celebrity and people are eagerly eating up whatever you say.
One place that seemed more compelling to me is the second half of part two, in which he dissects his attitudes to life and figures out whom he got them from. But nothing comes of it.