The ancient Nordic saga, the Elder Edda, says that the Well of Remembrance is located at the foot of Yggdrasill, the world tree. It confers on anyone who drinks from its waters the ability to see in new ways and to tap into the ancient knowledge and wisdom of Earth and mankind. As the saga relates, Odin, hearing of this well, desired to drink from it, and he approached the well’s guardian, Mimir, (from whose name the word memory comes) to ask for permission. After questioning Odin, Mimir agreed, but first told Odin that there would be a price–it would cost him one of his eyes. Odin agreed and gained what he desired, but forever after he saw this world through only one eye. (p15-16)

From Sacred and Herbal Healing Beers: The Secrets of Ancient Fermentation by Stephen Harrod Buhner