Being inaccessible and unavailable

[Nu Lang]

Yes, the sad thing for Achilles is he didn't know his heel was not protected, and becasue he didn't know there was no action he could have taken to remedy that. So to know is to be able to do something about it to change it. It starts with knowing, that's the first step, then doing based upon what is known. Then correcting as you go along because what you know changes when you know more.