He saw the world as flat.

Perpetually one eyed, except in gruesome battle, Kakashi saw the world as two dimensional.

But he was a man of layers. Layers, and armor, and masks. Beneath the underneath, he was made of blood. Blood that held secrets and that leaked like pain.

Of course, the world had layers too – the people around him and the other villages. He knew because he'd peeled back their layers, found the secrets and the blood.

It had been his job for so long, after all.

But it was an ugly job, and no one in their right mind liked seeing the pain leaking out of someone. Kakashi did like to pretend he was in his right mind.

So he closed one eye without complaint, and hid his face, pretending to fit into the flat world he saw. The flat, two-dimensional world that had no pain or blood or secrets.

And if the situation called for it, he could cheerfully close his remaining eye and shut out the world completely so he couldn't see what it was missing. Only then could he smile.