Siddhartha is nothing less than a seminal piece of classical literature. Hesse's succint and subtle prose delivers the goods in the Dostoyevskian manner: a polyphonous style of presentation where characters are self-conscious mouthpieces of ideas that exist within and for others. The main character undergoes several adventures on his journey of self-discovery: which is basically that knowledge may be exchanged, but true wisdom cannot.
In the final chapter, Govinda the sidekick confronts the protagonist and asks for his supposed wisdom. Siddhartha makes several Nietzschean points: the denial that wisdom can ever be taught, that any assertion of truth excludes what is false, but the world isn't as one-sided, that since time is an illusion the world is not progressing to a better, more perfect state of being. It is already perfect. (The Heraclitus/Nietzsche promotion of the eternal changing flux, the Becoming over static Being is all too obvious here) The dual nature of existence - sin and divinity, pleasure and pain, love and hate, life and death - is necessary. This echoes Nietzsche's Amor Fati. In order to renounce worldly goods, Siddhartha had to experience their bewitching allure first hand. Siddhartha claims that transcendence - the comparison of the world to some imagined perfection - inhibits the ability to love the world. Even the refusal to differentiate between words and thought is Nietzschean, more precisely, Wittgenstienan. Even though his thoughts do not cohere with the teaching of the Buddha, Siddhartha blames the distinction on mere words, and in the end the only thing matters is that he agrees with what the teacher did, not what he said.
Govinda, upon hearing him out, also notes that, despite the apparent distinction from the tenets of Buddhism, Siddhartha also has attained what the Gotama did: "... out of his gaze and his hands, his skin and his hair, out of every part of him shines a purity, shines a calmness, shines a cheerfulness and mildness and holiness, which I have seen in no other person since the final death of our exalted teacher." Siddhartha's journey is codified by Andre Gide's maxim: "Believe those who seek the truth. Doubt those who find it."