It is about this very abstract sense of displacement that he feels the moment he turns off the television.
Ideas which have been developed simultaneously or in immediate succession in the same mind mutually reproduce each other, and do this with greater ease in the direction of the original succession and with a certainty proportional to the frequency with which they were together.
Music rhythms are mathematical patterns. When you hear a song and your body starts moving with it, your body is doing math. The kids in their parents' garage practicing to be a band may not realize it, but they're also practicing math.