We think our version of a happy life as more like physics than like pop songs; we expect the people of the next century, say, to agree with our basic tenets — for instance, that broccoli is good for a happy life and that opium is bad — but they will not. Our rules for living are more like the history of pop songs. They make their weird sense only to the people of each given time period. They aren't true.
--speaking about her book The Happiness Myth: The Historical Antidote to What Isn't Working Today (2007)