Someone who is broke and comes into a million dollars can radically improve his life, buying a house and a car and so on. The next million dollars after that is still nice to have, but doesn’t improve living conditions nearly as much; now we’re talking about a somewhat nicer house and nicer car, which are good to have but not life-changing.

Now jump ahead to people with the kind of net worth that the C.F.O. of one of America’s most valuable companies has (Mr. Pichette owns $87 million worth of Google stock, according to tabulations from S.E.C. filings). Or consider someone who has earned tens of millions of dollars in the N.F.L. like Mr. Willis (who has received a total of $42.6 million in cash compensation, according to Spotrac, and we’re assuming for the sake of argument that he has saved a good chunk of it).

At that level of wealth, each additional million dollars in income results in very little net improvement in quality of life. For Mr. Pichette it might mean upgrading his private jet time share from a Gulfstream IV to a Gulfstream V; for Mr. Willis, it might be a giant mansion versus a really giant mansion.

It is easy to imagine that those feel like small improvements relative to the trade-offs: for Mr. Pichette, the opportunity to travel the earth with his remaining days living on it, and for the football players, better odds of being able to walk unassisted in middle age. (Pro sports, and the N.F.L. in particular, carry a different set of incentives for early retirement than the corporate world, where you butt heads with colleagues only figuratively.)