"It lives not, yet it cannot die," is a strange motto for a television show, but it works for The Late Late Show. Its continued success makes no sense to anyone – the producers, the audience, the guests or Ryan Tubridy himself, and it cannot be altered without a constitutional amendment.

Oh, some elements “change”, but these are superficial. There’s that jazzed-up theme tune from the show’s band of the damned (they once played Rosanna Davison’s wedding). There’s a new set, seemingly the attic of an abandoned factory (just off camera, interns keep roving hobos and wild dogs at bay). And Gay Byrne’s paternalistic gaze has been replaced by Tubridy’s haunted eyes.

“Oh my God, I’m still here,” they seem to say at the start of each episode.

“Oh God, so are we,” say the audience at home.

When Tubridy got the job, it was heralded as a big career move. We now know it was actually the result of a gypsy curse. “Hey Kenny, what was that you slipped into my pocket?” I imagine Tubridy saying in the RTÉ canteen as Pat Kenny ran for freedom. “A wizened monkey paw? What’s the significance of this? Kenny? Kenny!?”

A typical Late Late Show is all over the place. The most recent begins with ensmuggened chef Marco Pierre White wearing a woollen smock like a French peasant who eats smaller French peasants, talking about his gardener.

Harangued a socialist

Then Tubridy harangues a socialist. He starts asking about Paul Murphy’s apparently Fine Gael relatives. “[That’s] like when people say your family is Fianna Fáil,” says Murphy (Tubridy was gifted to RTÉ as a child tribute by the party in the 1980s.) It ends with him tetchily asking Murphy to condemn behaviour he has already condemned and to guarantee behaviour from protesters he can’t guarantee. There’s a real discussion to be had about the boundaries of civil disobedience, but against such pre-emptive disapproval Murphy is measured and patient, while Tubridy seems blasé about the arrests of protesters.

When not being combative on behalf of a middle Ireland which doesn’t exist, Tubridy is a good interviewer, as he proves when talking to calm, dignified Linda Boland, whose mentally ill brother killed her father. And the show ends with likeable Elaine Crowley speaking about her life, family and depression.

Crowley is from TV3 and has never been in Montrose before, which makes this segment like when Sean Connery visits the home of the Eternals in Zardoz. "What is love?" Tubridy wants to ask, but instead says: "Why are you single?", like an inappropriate uncle at a wedding.

Oh, and I nearly forgot, in the middle there is a sing-song because someone has left both Chris de Burgh and a guitar on the couch.

"Ah s**t, Chris has seen the guitar," I say, which is usually my reaction when this happens at parties. Then I remember that I like Chris de Burgh. He sings Spanish Train, which is about God and the Devil on a haunted train; Patricia the Stripper, a jaunty ditty about the sex industry; Don't Pay the Ferryman, a song about exorbitant transit fees (I think); and A Spaceman Came Travelling (but not by ferry obviously), which Tubridy asks de Burgh to explain. Jesus might have been a spaceman, explains de Burgh. "It's there in the lyrics, Ryan!" I shout at the telly.

Wake with scars

As Chris plays, the camera keeps cutting to the glassy-eyed studio audience clapping along looking confused. It's happened to us all. You're minding your own business in a bar, then you blackout and wake with scars where your kidneys should be, groggily singing along to Chris de Burgh in a Late Late Show audience.

Then de Burgh introduces a new song, The Hands of Man. "The things that we can do with these hands . . ." he says, "particularly thumbs." Which is brilliant. He should have called the song Particularly Thumbs. And I might borrow that name when I start my mitten shop.

Anyway, some of this is entertaining and much of it infuriating and together none of it makes sense. All of these items are so tonally distinct any sane producer would put them in separate programmes. But the Late Late Show is madness itself. It's too long and less than the sum of its parts. Elsewhere, chat shows have morphed into shorter, wittier celebrations of celebrity good-sportsmanship. Even locally we have the zippier Saturday Night Show (Tubridy and Brendan O'Connor now fight for our damned souls like God and the Devil in Spanish Train). But The Late Late Show cannot change, because nobody knows why or how it works.

It survives, sustained by tradition and spite and the fact that it's older than Newgrange. Each week we watch in vague remembrance of Gay Byrne putting condoms on bananas, being patronising to disobedient women, or doing hard-hitting interviews with Judge from Wanderly Wagon. We trudge into our sitting rooms as though the theme tune were the call to prayer, because like Fine Gael or the weather or the music of the Script, it's no better than we deserve. They should put it in the ads really. "The Late Late Show: It's no better than we deserve" or "The Late Late Show: It was always thus" or maybe even: "The Late Late Show . . . sure, what did you expect?"