Both parts of Don Quixote form a veritable encyclopedia of cruelty. From that viewpoint it is one of the most bitter and barbarous books ever written.
Of course, Nabokov then goes on to say that its cruelty is "artistic," but "artistic cruelty" is markedly far from "continuous gaiety."
So, who is perceiving Cervantes' encoded meaning correctly? Those of us who find the adventures of "the Knight of the Sorrowful Face" overwhelmingly sad, or those who find a whirlwind of comedy and...yes, I'll say it again..."gaiety"? Or is the secret, perhaps, that the work's open-armed acceptance of differing interpretations is a characteristic that makes it a cornerstone of literature, and one of the greatest books ever written?