Forgive me if I've misread, but I think what you're putting forth as acknowledged fact here is in fact controversial. You seem to be referencing the 1978 study "Lottery Winners and Accident Victims: Is Happiness Relative?" as well as, perhaps, the idea of the Hedonic Treadmill. Brickman's ideas are considered outdated.

http://www.ncbi.nlm.nih.gov/pubmed/690806 http://en.wikipedia.org/wiki/Hedonic_treadmill

That's not to say that working, alone, producing happiness is a correct idea, but it might make sense that accomplishment does. And these levels of accomplishment - cleaning the floor well for a janitor, for instance - can differ. Most people desire to "make a difference," another way of saying the same thing. If you're talking about deathbed wishes when looking back on a life, the more positive impact your life visited on others, the better.