Cofty,...of course the tools the human brain can devise are exactly within the capacity of human understanding ie the brain has reasoned beforehand as to why such things as you have mentioned are constructed. My point is the physical make up ie tissue, nerve, proteins all have a limit we cant go beyond it unless something is added to the mix.
It begs the question imo that there may be "things"beyond our actual capacity of understanding.
The spark of creation for example we can only ever investigate within the constraints of our capacity, otherwise you would have to argue our brains have limitless capacity.
Everything in our world that we understand has a defined beginning and will ultimately end.
The enigma of the universe/cosmos does not at our present understand seem to conform to our human rational, as we will always wonder what caused the initial spark and so on to infinity.
Perhaps someday.
Best wishes