When you say "I don't know", are you affirming existence or nonexistence? Or rather, you are well beyond those extremes?
Affirming non-existence of knowledge.
When you say "I don't know", where do you dwell?
When you say "I don't know", what is your support?
When you say "I don't know", where is your intellect?
Your intellect is supporting the view that it does not know.
To know is to believe something is true, have intellectual support for it, and dwell in this view.
I can know that something is not true.
"If you understand anything, you don't understand. Only when you understand nothing is it true understanding. The sutra say "Not to let go of wisdom is stupidity""- Bodhidharma"
The ignorant also do not understand, does that make them wise or stupid? You have to understand (that nasty word again) that Bodhidharmas advice is a) to not fall into the trap of considering Buddhism an intellectual pursuit and b) that enlightenment has nothing to do with a "you", thus if "you" think that "you" are enlightened (ie have true understanding) then "you" have not truly understood anything.
PS Again, like I said at the beginning of our conversation, you are falling into nihilistic view due to a misunderstanding of the nature of the two truths. This is a common mistake, we all make it at some point in time (and some of us continue to make it
). I am not launching a personal attack on you, nor am I judging you. If you do not want to heed some friendly advice then...