次の英文の下線部を和訳せよ。
People forget how important it is to be lazy in libraries. Not of course idle: idleness means daydreaming. Laziness means reading the books one ought not to be reading, and becoming so absorbed in them that at the end of the day you still have most of the reading to do that you had before you that morning. Creative laziness broadens the mind. [東大]