The story of the hero of time has been told to each child born since the dark king's defeat. As the child gets older the story become darker, gaining more details being more realistic, more truthful. By the time the child is twelve they are told the full story as the hero would tell it. Then around the time they come of age at sixteen years old, they are told about the shadows.
Each person has one, they are dark and can move through the shadows, they can stow away in them. Each child is told to stay quiet about it, they wouldn't want to make the younger ones more scared of the dark. It is a well know fact that you can not kill a shadow. For no matter how much you run from your shadow it will always follow. Even if you shine a light on it, part of it stays and it always comes back fully.
The shadow of the hero of time escaped into hyrule field after his defeat in the water temple. He found his way into the ranch outside of Hyrule castle town. He tortured the young maiden there for months, then he became interested in her physically. Then the hero of time came and slayed the shadow once and for all with the master sword. Then he married the young maiden.
But the hero didn't actually kill the shadow, again the shadow ran off. He hasn't been seen since. And life did not slide smoothly for the young girl affected by the hero's shade, a child grew in her womb. At first the hero was happy, it never crossed either of their minds that the little child wasn't his. Then two months early, it was born.
The child had golden eyes and skin as pale as the moon. The hero continued to love the maiden but did nothing with the child. Then the child's hair came in black as night. The hero tried to rid himself of the child but the maiden wouldn't let him. She fled into the night, with her child to a small town called Ordon.