I can understand; but I may not try to understand ‘Understanding’. I can do a lot of things with ‘Understanding’. But I may not try to understand it.
Mind may not mentate about Mind. You can mentate about all things in this great and grand universe of ours. But you may not mentate about Mind.
Consciousness may not grasp at consciousness. Thought may not seek its beginnings in another thought. Concept may not conceive itself in another concept.
Logical Symbol may not grasp for its genealogy using other symbols of Logic, nor Mathematics in the axioms of Mathematics.
Language may not seek its source using Language. Word may not seek its meaning through other words.
I may not seek for the definition of the word ‘Knowledge’ while in the ‘Know’. I may not search for the ground of ‘Being’ while in the ‘Be’.
And ‘I’ may not inquire about ‘Me’.