I have very little to go on because my knowledge comes from American culture comes from American TV and movies, which very rarely mention anything about class. That said, an episode of The Fresh Prince of Bel Air I caught last week had an English character explaining to an American character the concept of social class as distinct from one's current wealth (the example given is that a housekeeper who wins the lottery is still working class, and a deposed queen who's completely penniless is still upper class), and it's presented as a baffling difference/gap of understanding between cultures.