David Letterman’s last weeks.

Now that Letterman’s a flinty codger, an establishment figure, it’s become difficult to recall just how revolutionary his style of meta-comedy once felt.

.. In a sense, Letterman was a bridge between two eras of male superstars. Like the white-guy comedians of the seventies, Bill Murray and Chevy Chase and Steve Martin, he was a smart-ass, a trickster. And yet, even in 1982, when “Late Night with David Letterman” premièred, he presaged something else, an obsession with what was authentic, the kind of preoccupation that would dominate the nineties, inflecting figures like David Foster Wallace and Kurt Cobain, famous men who were desperate for rock-star fame and then flamboyantly and publicly hated the stuff once they got it.

.. His influence spread so wide that his innovations became clichés. Once the Internet arrived, he never mastered the viral clip.

Will you miss Mad Men? James Delingpole won’t

They chain-smoke and booze and fornicate like there are no consequences, for in Mad Men there really aren’t. Sure your career might go up and down and there might be some heartbreak, but you never once lose hold of the really important things — your looks, your style and your cool.

.. it also points up the underlying theme, which is about identity, and the contrast between surface gloss and concealed dross.

.. obsessive creator Matthew Weiner (a protégé of David Chase, the man behind of The Sopranos — on which Weiner spent several seasons as writer/producer) whose anally retentive attention to detail is legendary. On one occasion, he famously dismissed a bowl of plump, shiny apples from the set on the grounds that Sixties fruit was smaller, dumpier than today’s.