Odin was the chief god of Norse mythology. He was also called “Wanderer” because of his many journeys. Once, he found a giant guarding a well. When asked for his name, the giant replied: “I am Mimir, and this is the Well of Knowledge. You may drink from it if you give me one of your all-seeing eyes.”

Odin took out one of his eyes, then drunk from the Well, and was, forever after, the wisest of Gods.