Of the threads through Graham Linehan’s comedy-writing career, perhaps the most curious has been his continual drift towards the studio audience.
Even by the time of Father Ted , which he wrote with Arthur Mathews, the notion of herding in a studio audience was becoming old fashioned.
By the time The IT Crowd came along, in 2006, it was so out of fashion that he grew cranky dealing with requests for the "canned laughter" to be dropped.
The IT Crowd is to film a final episode, some three years after its fourth series, and finally round off Linehan's deliberate move away from the mockumentary style that then riddled the comedy schedules.
Linehan has always appeared to straddle TV eras, as comfortable in the deep surrealism of sketch shows such as Big Train and Jam as he was when creating or collaborating on sitcoms – Black Books , Father Ted – that were innovative even while rooted in long-standing traditions of television comedy.
Yet to bring in a live audience – to let the cast pause on a joke as a backwash of laughter receded – was a stubborn thing to do in the age of The Office , The Royle Family , Early Doors , How Do You Want Me , The Thick of It , The League of Gentlemen and so many others.
Even in Ireland there was a brief flourishing of brilliance in the forms of Paths to Freedom and Bachelor s Walk . (Both have been denied a second life of repeats on RTÉ but would be fascinating to watch now, not least because they seemed so of their time as to warrant a place on the history curriculum.)
I was this newspaper’s television critic during the early to mid-2000s and, blinkered by the narrowness of experience, fell in with the prevailing argument that the traditional sitcom was dead, buried by sophistication and no longer to be tainted by laughter.
It was, it seemed, an inevitable, final evolution. After the 1970s and 1980s, sitcoms would never again be seen dragging their knuckles as they walked through their plots.
How wrong that proved. In Britain the sitcom has reverted to what now appears to be its natural state. It was aided by the trend-bucking My Family , Not Going Out and The Vicar of Dibley before being followed by waves of scripted sitcoms, from Miranda to Ben Elton's current, critically mauled The Wright Way .
Mrs Brown's Boys is probably the most-discussed example, yet Brendan O'Carroll's surprise success has, accidentally or otherwise, echoes of Sean Hughes's brilliant 1990s fourth-wall-dispensing Sean's Show .
Back then Hughes's show would have been described as postmodern. People don't say postmodern anymore. And certainly not in connection with Mrs Brown's Boys .
The sitcom has not lurched so much in the US. There, networks have struggled to replace the genre-defining brilliance of (the live-audience stalwarts) Seinfeld , Friends and Frasier , yet there are riches galore.
The traditional sitcom has its place, but the breadth of US television has allowed the likes of Parks and Recreation , 30 Rock and Modern Family to flourish. The Office , whose influence in Britain ultimately morphed into cliche and became stifling even for Ricky Gervais, has lived on in its US incarnation for nine years, finally coming to an end only this week.
But it has also seen a true evolution. Although Curb Your Enthusiasm featured Larry David as a gnarled, diseased branch growing from the Seinfeld tree, Louis CK's current comedy Louie (showing here on Fox) has reshaped the comedian-as-sitcom-star format in startling form: it is often plotless and veers between naturalism and surrealism without warning the audience.
In Britain, it could be argued, there hasn't been great sitcom innovation since the first-person camerawork of Peep Show . But innovation isn't what matters. Laughs are what a sitcom craves.
Curiously, Linehan's intention to make a more traditional sitcom in The IT Crowd has been credited with boosting the reputation of that genre and ushering the studio audience back in front of the sets.
It hasn't necessarily been his most successful show – it has too often fallen as it reached for Seinfeld -like plot structures – but in being old fashioned it turned out to be a harbinger of change. In the process it confirmed a key element in Linehan's genius: he is a writer for all decades, his comedies timeless.