There may be and probably is a vast realm of reality co-existent with the reality we know, right around us; but it is "screened" from us. It may be possible that we know less than ten percent of actual reality around us due to the screening of our senses and our instruments that blocks completely, or permits to pass completely, every energy pattern that can't pass through the "holes" of our "screen."
Going back to Kah, the one-inch-rock-universe observer, suppose that in one batch of dirt dumped at the head of the screening system there happened to be no one-inch rocks at all? Or, more closely to the story you are about to read, suppose, with his mind deeply grooved with the tracks of the one-inch rocks, he were to move to a vantage point where there were no one-inch rocks, but larger or smaller ones?
He would immediately find nature behaving according to an utterly strange pattern, BUT he could only sort the incoming sensations according to the neural grooves already built up in his mind! In his mind he could only see one-inch rocks or nothing, and since what he would see would obviously be something, it would either seem nothing to him, or one-inch rocks behaving strangely.
His instruments and his mind would interpret by the old gradations and scales and concepts. His Universe would still be made of nothing but one-inch rocks, to him, but its behavior would be strange.
Perhaps slowly, like a newborn child making sense out of its surroundings, or a foreigner slowly making sense out of our language, he would penetrate to the new reality with his mind. Perhaps in the very process his being would change its structure.
In the end he would be in a unique position. He would have the memories of one Reality, and the experiences of a new one. He would have the language of the old with which to describe the new to his old companions. Could he do it so they would comprehend it?
It would do him no good simply to invent new words to describe something beyond the experience of his old companions. He would have to describe something beyond their experience with words and sentences they had created to describe only what they had gained from their own experience! How could he hope to make them gain a true understanding of it?
He might tell them simply and truthfully everything he experienced—and it might come out utter nonsense! It probably would. Unless he could bring back some of the evidence, either intentionally or unwittingly.
At first that evidence might present a pattern of utter nonsense and contradiction with known thought patterns and concepts. It might present seemingly normal events in nonsense sequences. It might present impossible events in seemingly normal sequences. It might even present disjointed events in sequence.
What it would present would be only what the screen of the senses and the screen of the mind could accept. Underneath would be a perfectly orderly pattern of events of some sort, behaving according to different natural laws in conflict with those we have existed under. Slowly we might penetrate to an understanding of them, but not at first, because at first they would be completely UNTHINKABLE.