Poor people know poor people, and rich people know rich people. It is one of the few things La Rochefoucauld did not say, but then La Rochefoucauld never lived in the Bronx.
Moss HartA too constant preoccupation with money may seem to indicate the lack of a proper sense of moral values, but [let] those who have always had money . . . be without it for a while, and they will soon discover how quickly it becomes their chief concern.
Moss Hart