Men think that they can distill reality and the true nature of all things into 'this or that quaint theory or explanation'. But how does this explanation include this act of explanation itself?

Quite simply, you can't "know it all" because "you" aren't "it all", neither do you perceive and understand all things. And no matter what you do say, none of these things can bring any of us any closer to knowing "who we are" or

Why THIS IS

Who? Why? Who am I?
Why am I?
Why am I trying to Know?

None of the materialistic explanations will suffice because they deny that I am.