Beelzebub's Tales to His Grandson

Beelzebub's Tales To His Grandson is, without a doubt, one of the weirdest books I have ever read. Written by Armenian mystic Georgei Ivanovitch Gurdjieff it details an imagined dialogue between alien spaceship captain 'Beelzebub' and his grandson as they traverse the solar system, flying towards Earth. Beelzebub explains that the human race see everything upside down due to the after-effects of the vestigal organ 'kundabuffer', which was once installed within humanity to help the Earth through a cosmic catastrophe, but which now blinds the human race to its true nature.
The true appeal of this book is that it's not simply barking - there's much non-barking allegorical meaning to be gleaned from a text that the author claims to have written whilst binging on Calvados in the basement of his Fountainebleu estate in France, surrounded by the prominent thinkers of the day. Check it out.