Zarathustra was a Aryan prophet, he lived among the Indo-Aryans in the Eurasian steppes in 1450 BC, during a period known as the Bronze Age, where the the people worshiped pagan gods such as Mithra, the goddess of light. Then Zarathustra introduced a concept known Ahura Mazda, a Wise Being who live only according to his or her own wisdom and morality. Friedrich Nietzsche understood this introduced the Overman in Thus Spoke Zarathustra or "SuperHuman" in German, which is a person who breaks away from the herd mentality and lives by his or her "will to power". The SuperHuman is achieved through the six Amesha Spentas. We must understand Zarathustra was not a leader instead he was a guiding people to follow their own wisdom. Zarathustra was the pioneers of humanism but most of his true philosophy went into decline after the Greek invasion of Persia, and the introduction of personification of Greek gods to the Persians.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

When Zarathustra arrived at the edge of the forest, he came upon a town. Many people had gathered there in the marketplace to see a tightrope walker who had promised a performance. The crowd, believing that Zarathustra was the ringmaster come to introduce the tightrope walker, gathered around to listen. And Zarathustra spoke to the people: