Freud published it in 1899, dated it 1900, and called it the most valuable of all his discoveries. Dreams, he argued, are the royal road to the unconscious; they represent wish fulfillment, disguised by censorship. The book contains his own dreams, his patients' dreams, case studies, and the theoretical apparatus that would shape twentieth-century thought. Whether you accept the theory or not, the book changed how we think about the mind. The prose is lucid, almost novelistic. Freud was awarded the Goethe Prize for literature, and you can see why.