A good reminder to have on your wrist, regardless, but this is also a VERY subtle reference to a passage in Nabokov. It is at the end of a chapter, and the narrator poses a whole series of impossible, seemingly rhetorical questions, mostly about the meaning of life. At the end of this list are these words, taking the whole thing from being a silly, thoughtless rant, to a genuine question, making you actually try to think of the answers.