How do you know what cannot be known? Do you mean to suggest that what you feel you "cannot know" is ultimately, truly unknowable on principle?
For instance, Hank says the future cannot be known. But math and physical laws work against that view; for instance, as soon as I press "post" I shall add 2 plus 2 in decimal and I know the answer will be 4 in decimal.
Further, I perceive all that there is to include extra dimensions, one of which is time, and therefore time is a plane and not a line and thus, not only is the future, past and present known in that dimension but it may also be knowable in 4D.
Likewise, by the grace of God, I know Him and perceive many things which are not knowable to one who does not have the eyes to see or the ears to hear. But others who share the same Holy Spirit are of the same mind; we perceive spiritual matters as One being.
Which things also we speak, not in the words which man's wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual. But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know [them], because they are spiritually discerned.
But he that is spiritual judgeth all things, yet he himself is judged of no man. For who hath known the mind of the Lord, that he may instruct him? But we have the mind of Christ. - I Corinthians 2:11-16
So what would be the point of trying to define "what cannot be known"?
Of course we cannot know what cannot be known, but we can know some kinds of things which cannot be known. I suggested a couple in post #113. We cannot know things which are just not available to us to know. We cannot know factually any detail of the universe beyond a certain distance, because the light from those parts of the universe has not reached us yet. We can conjecture and make intelligent guesses what it might be like in general, but cannot know the detail.
It has nothing to do with feeling.
Hank