Bran Stark:Growing up, my sister Sansa loved stories with princesses and knights, but I always wanted to be scared. When my turn came I would ask Old Nan to tell us of magic and monsters.
Long ago, when the world was new, the Children of the Forest sang the song of the earth, and the earth listened. Magic was strong in those days... and the Children could commune with all the beasts of the forests, streams and air. The greatest of them could even leave their bodies to hunt, swim and fly in the skins of animals. They were the first wargs.
Then, the First Men came with fire and sword. They burned the weirwoods and cut down the Children. Calling on dark magic, the Children raised the sea and shattered the land bridge that the First Men had crossed into Dorne. When that failed, the Children brought down the hammer of the waters upon the Neck, flooding and transforming it into the bog it is today. After peace came, the two races shared the land and the Children's gods for thousands of years.
Now comes the good part: nobody knows how or why, but the magic of the Children began to... emerge in men. Maybe one child in a thousand would be born a warg; fewer still would be born with the Sight. Old Nan would not speak of it, and MaesterLuwin never believed in it; but with it, the Children could know of events far away and even those still to come. Some say the Sight was the Children's most powerful and terrible secret, and helped turn the tide during the Long Night.
But even wildlings keep their distance from a warg because - and here Old Nan would lean in close and whisper - how can you tell if the man is wearing the beast or the beast is wearing the man? Now Old Nan has no more tales and Maester Luwin will never scoff again. That's fine, I don't like scary stories anymore, because... I'm in one.