A Footnote From Christopher Hitchen's Memoir, "Hitch 22"

An old joke has an Oxford professor meeting an American former graduate student and asking him what he's working on these days.  "My thesis is on the survival of the class system in the United States."  "Oh, really, that's interesting: one didn't think there was a class system in the United States."  "Nobody does.  That's how it survives."