Most of us know the story of Achilles, the Greek warrior whose mother tried to protect him from an early death by submerging him in the magical waters of the river Styx. Despite her best efforts, she missed dunking one heel that she gripped as she dipped him upside down in the river. And as fate would have it, a poison arrow to this single weak spot led to Achilles' demise. By most accounts, he was still a very young man.