I couldn't disagree more strongly with the negative reviews (which seem to form the majority consensus).
This is a book for those who delight in the profundities of the "inner world". It is an unashamedly challenging read, a book of depth and real intellectual veracity (unsurprisingly from an author who is a Professor of Philosophy). It is a book, above all, for those that delight in the art of critical thinking, for those that choose to examine the nature of their own reality. Various themes are explored through the exploration of Perlmann's neurotic inner life. No formal academic knowledge is required to comprehend the underlying philosophical, linguistic and psychological ideas presented; intelligence, careful thought, and patient engagement are. It is a brilliantly crafted, incredibly penetrating analysis of the fractured consciousness of a man reviewing his life choices, the projection of self and the social role.
If you're after a light, throwaway piece of entertainment fiction, look elsewhere.
If you're the sort of person who enjoys reading such thinkers as Kant, Chomsky, Foucault, Goffman, Adorno, for example - in other words, if you enjoy reading Philosophy or engaging deeply with ideas - you will most certainly enjoy reading this novel.
The novel is also beautifully written. A couple of examples:
"He almost felt dizzy when he concentrated intensely on the notional point of experience that could be achieved were he to succeed in dismantling the structure of his anxiety piece by piece and transfer it into another way of feeling."
"...their unchanging, monotonously updated expectations, which they treated as if people developed in an uninterrupted, linear fashion - as if the successful life consisted in making those professional decisions that were taken early, too early, and that hardly ever merited the name in any case, in total identification, with a complete lack of emotional detachment, decade after decade. What do you want to be? You have to be something. Whatever would become of him? Those were the principles his parents expressed over lunch and dinner."