The best way to use the book is to consider it as a) a product of the setting it attempts to describe, warped by the twisted nature of the world that produced it or b) the way an actor considers a mask – looking for the shards of meaning that will tie the whole thing together. Certainly, read it all (at least twice) before you dismiss it as mere rambling. Take the introduction seriously. We did.
Normality always provokes a very strong reaction when it first is encountered. Comments range from rejecting it as incomprehensible to praising is as sublime genius. In any case, the core rulebook is very difficult to approach.