Happiness' biggest killer is thinking about the future / dwelling on the past. I think smart people do this a lot more, which may explain the correlation. From

Happiness' biggest killer is thinking about the future / dwelling on the past. I think smart people do this a lot more, which may explain the correlation. From Buddha to Eckhart Tolle almost every book and teaching about happiness boils down to living in the present. But I guess it's much easier said than done because our minds like to wander (evolution to anticipate dangers perhaps?) and living in the present is like keeping your balance on a stationary bicycle with gravity always working against you. But fwiw we do get glimpses of true happiness say when you're like in the zone and totally immersed in the task at hand that you're thinking of nothing else and just happy (doing what you're doing).