Hill didn’t know he caught it, because he could have had his eyes closed and the result would have been the same. It’s better to be lucky (reeeeally lucky) than good.
btw: Here is Collinsworth’s analysis of that play:
“Did you see the way that Mahomes purposefully threw the ball to the defender, knowing it would pop into the air and blindly land in Hill’s hands. Amazing!!! Mahomes is too good for this world... he is literally an angel and the rest of us are merely worms in his forces. Mmmmm, so warm in there.”