A vast body of psychological evidence shows that the pleasures of consumption wear off through time and depend heavily on one's frame of reference. Most of us, for instance, occasionally spoil ourselves with outbursts of deliberate and perhaps excessive consumption; a fancy spa treatment, dinner at an expensive restaurant, a shopping spree. In the case of the very wealthy, such forms of consumption can become so commonplace as to lose all psychological benefit: constant luxury is, in a sense, no luxury at all.
Graeme Wood -
Atlantic Monthly article, The Fortunate Ones