A biography?
Well yeah, let me tell a story.

The Shadow and the Light are... well rivals? Maybe you can say it. But sometimes they talk to each other.
"So why are you always hiding? Stand in front of me!" Said the aggressive Light.
"No." Said the quiet Shadow.
"I can wait. I know you're there." Said the patient Light.
"OK." Said the quiet Shadow, and they fell silent.

Time went by. One day, they restarted the conversation, this time the starter was, surprisingly, the Shadow.
"Can you think of anything other than hide and seek?" Said the meditative Shadow.
"No, why this question? There's of course nothing else except us, and this hide and seek game." Said the enthusiastic Light.
"So we are ALL." Said the meditative Shadow.
"We AND the game are ALL." Said the proud Light, and they fell silent again.

They talked no more. They have nothing else to do, so they keep playing the game patiently forever.

That is enviable for you, right?