In the words of my prof, "Y'know what, sometimes the curtains are just fucking blue... but we don't read trash in this class. So when the curtains are blue--it means something."

(And no, he didn't mean to make stuff up about the sybolism of blue curtains and snowballs-- he meant, that good books are meaty with ideas. They tell you about the values, the era, they tell you where the characters are coming from. They paint a meaningful scene when taken as a whole.)