Odin watched the Norns from his seat in Asgard and envied their powers and their wisdom; so he bent his will toward the task of coming to know the Runes.
The Runes do not reveal themselves to any but those who prove themselves worthy of such fearful insights and abilities.
Odin hung himself from a branch of Yggdrasil, pierced himself with his spear, and peered downward into the shadowy waters below. He forbade any of the other gods to grant him the slightest aid, not even a sip of water.
And he stared downward, and stared downward, and called to the runes.
At the end of the ninth night, he at last perceived shapes in the depths: the Runes! They had accepted his sacrifice and shown themselves to him.