When Odin went to Mimer to ask for a draught from his precious spring, he was growing impatient of the sparling water when Mimer the Giant refused. Only the the giant ask for a boon in exchange for the draught--leaving
one of Odin's far-seeing eyes at the bottom of his well.
Odin hesitated. It was indeed a
heavy price, and one that he could ill afford, for he was proud of his noble
beauty. But he glanced at the magic fountain bubbling mysteriously in the
shadow, and he knew that he must have the draught.