“Can you not see,” I said, “that fairy tales in their essence are quite solid and straightforward; but that this everlasting fiction about modern life is in its nature essentially incredible? Folk-lore means that the soul is sane, but that the universe is wild and full of marvels. Realism means that the world is dull and full of routine, but that the soul is sick and screaming. The problem of the fairy tale is—what will a healthy man do with a fantastic world? The problem of the modern novel is—what will a madman do with a dull world? In the fairy tales the cosmos goes mad; but the hero does not go mad. In the modern novels the hero is mad before the book begins, and suffers from the harsh steadiness and cruel sanity of the cosmos. In the excellent tale of ‘The Dragon’s Grandmother,’ in all the other tales of Grimm, it is assumed that the young man setting out on his travels will have all substantial truths in him; that he will be brave, full of faith, reasonable, that he will respect his parents, keep his word, rescue one kind of people, defy another kind, ‘parcere subjectis et debellare,’ etc. Then, having assumed this centre of sanity, the writer entertains himself by fancying what would happen if the whole world went mad all round it, if the sun turned green and the moon blue, if horses had six legs and giants had two heads. But your modern literature takes insanity as its centre. Therefore, it loses the interest even of insanity. A lunatic is not startling to himself, because he is quite serious; that is what makes him a lunatic. A man who thinks he is a piece of glass is to himself as dull as a piece of glass. A man who thinks he is a chicken is to himself as common as a chicken. It is only sanity that can see even a wild poetry in insanity. Therefore, these wise old tales made the hero ordinary and the tale extraordinary. But you have made the hero extraordinary and the tale ordinary—so ordinary—oh, so very ordinary.”
G. K. Chesterton, "The Dragon's Grandmother" from Tremendous Trifles.