There are 4 states:
State 1) The Only Thing I Know For Sure Is That I Don't Know Anything For Sure.
State 2) Based on state 1's "emptiness" state in your mind , you start the journey to know Anything's true nature.
State 3) Even you know For Sure Things true nature , but you still not thinking that you know Anything For Sure.
State 4) Based on state 3, you probally have the real chance to know Anything For Sure.
RE: The Tao of Paradox | Part 1: The Only Thing I Know For Sure