'Art emerging like a foal fully formed into the world' and the truth of the matter was the modern art seemed to disappear and I never even looked at it....

It is a wonderful show, even though as you rightly say the light is dim and you have to shuffle around the exhibits in a queue. My favourite is two deers swimming, carved with such delicacy that it takes your breath away. The other was the head of a musk ox tucked into a corner, the curve of the brow and horns gave it such life.
We also saw the Herzog film, and the cave paintings, that is where the top quote must have come from, the sheer brilliance of those painted horses, bears, etc.