Tomorrow is the 40th anniversary of the first episode of Are You Being Served? an unlikely comedy show to become a worldwide hit, but a worldwide hit nevertheless, and probably because the characters do seem to represent a kind of Britishness that would be familiar (or at least suspected) to anyone watching from outside of the UK.

By which I mean, Are You Being Served? is what you think we’re like.

Many’s the tourist from far off places that has come to visit British department stores hoping to find some variation on Mrs Slocombe, Captain Peacock or Mr Humphries. Lord alone knows what their faces will have been like when confronted with the grisly reality of a world where no one, but no one, shouts “I’m free!” quite like that.

In any case, here are some of the key factors that made the show a hit:

1: The Eternally Repressed Sexuality Of All British People

Yep, it’s literally all any of us can think about from morning til night, because we can’t. Given an idle moment, the British sense of humor can be relied upon to make almost anything sexual, but the thing is, in order to act with proper decorum (’70s division) no one could ever admit it. This means that even the ugliest, most charisma-free of British sitcom characters (hello, Mr Rumbold!) can appear to have the throbbing sexual tension of your favorite pin up in your favorite fantasy, because he’s trying to hold it all back. Either that, or it’s just funny to make clean things into dirty things.

Speaking of which…

2: The Unexpurgated Filth Of Mrs Slocombe’s Favorite Pet

In 1993 (1993 though!) the comedian David Baddiel made the point that language had evolved since the early ’70s in such a way that makes this gag harder and harder to stomach. “In the 1970s when Are You Being Served? was shown, no-one swore on TV, so the word “pussy” just meant “cat” with perhaps a slight undercurrent of “vagina”. When Grace And Favour [sequel to Are You Being Served?] was shown in the 1990s, everyone swore on TV, so now, the word “pussy” just means “vagina”, with perhaps a slight undercurrent of “cat”.

Suffice to say a new comedy show with this as one of its core gags would struggle for airtime on either side of the Atlantic now.

3: Those Unambiguous Predelictions of Mr Humphries’

Again, what was once a risque little dance around the edges of a lifestyle that had only recently become legal has since become explicit. Now there’s no suggestion that Mr Humphries may be talking about dalliances with men (and isn’t it hilarious, the thought that he might be?), he’s actually throwing out details of his love-life in the middle of his working hours, to the total oblivion of almost everyone around him. How inappropriate. Like it or not, the ’70s were a boom time for the stereotype of the limp-wristed effeminate gay man, and Mr Humphries was the queen of them all.

4: The Rapid Delivery of Humorous Quips From A Variety of Sources

When it’s done right, TV ensemble comedy can be breathtaking, both in the sense of being impressive and literally leaving the viewer gasping for air. Each punchline arrives at right-angles to the feedline before it, and the feedlines can be punchlines too. Everyone acts according to their character motivation, seemingly innocuous events begin to unfurl, and suddenly four or five things are happening at once, and you can’t tell where the next laugh is coming from (except it’s probably not Captain Peacock).

5: The Corrupted Power Of Young Mr Grace

A very rich, frail old man, attended to by two attractive female nurses in skimpy uniforms, who is unsteady on his feet and yet given ultimate respect by his minions. “You’ve all done very well” is his catchphrase (cue fall back into arms of said nurses).

6: The Sharp-eyed Pomposity of Captain Peacock

He’s got a face like an eagle, and the calm, soothing demeanour of a roman emporor, but Captain Peacock, for all that he insists on decorum and order in all this, never gets it, because he is the straight man to end all straight men. Cross, pompous and domineering, and very seldom the winner in any encounter, he’s vital to the show’s unfolding mayhem. And what a perfect name he has too.

7: The Theme Music

We tend to take this fact for granted, but can you think of any other mainstream comedy show’s theme music that shares a basic soundtrack with a song by Pink Floyd? And guess which loop of cash registers reached the public first? Not the Floyd’s, although they do each seem to have been created in ignorance of the other.

So, happy birthday, Are You Being Served?, we shall not see your like again, and probably with good reason.

Fraser McAlpine is British, this explains a lot.