Did you know that Philip Roth is only the third American to have his work published by the Library of Congress?  He writes very well.  I love most of his novels, but like you I agree that this one was puzzling and harsh.  It did not seem to me that the he wanted it to be liked for its content, because the main character is not someone that you could get close to, or like.  Perhaps this book is about being successful in your work, but failing on a higher plain…that of the human connection.  This guy had three wives and lots of kids who could not really connect with him.  Even in his younger years, he had failed anyone who tried to love him.  He could connect with tangibles but not with family.  He loved women, but not just one women.  Usually an author will make comparisons between a person’s youth and their declining years.  In this book it seems like the main characters physical self, at the end, caught up with the lack of humanity that he always had; and this united those two unfavorable selves into an unlovable, living being.  This man left behind only the remorse of those who would have cared, if he had allowed it.  Wish I knew enough about the author to understand his motivation in bringing to life someone who never lived at all.