I remember studying marginal utility in microeconomics. The idea was that there were diminishing returns on happiness, based on the amount of a good or service consumed. I suppose that applying this to money itself could also makes a lot of sense. However, at some point, our focus on happiness became the societal focal point for motivation to do things in life. when there was a period of time when just being able to survive brought us happiness. From what Ferrer-i-Carbonell was saying, it sounds like there is a marginal utility for happiness itself, which is an interesting concept. Perhaps this has always been a motivator for continuing forward? Almost as if once we peaked in happiness with a certain activity, boredom itself would drive us to find other sources of happiness.