I agree with this to a degree. But on the other hand, perhaps he intends to live both an enjoyable and long life (like many Blue Zones people do) - not sure that they are mutually exclusive. And given that he is one of the leading scientists in the world in this area, he must get a tremendous amount of pleasure and reward (many multiples of chocolate mousse) from making discoveries that can improve people's lives (for e.g. some of his recent publications are concerned with fasting being potentially beneficial in relation to CVD, diabetes and breast cancer). And perhaps he want to live a long time so he can continue contributing in this way rather, than just for his own benefit. Probably he should have some kids though so there are some little Longos :)