The narrator of this comic first novel would be a strange bird in any society. How easy is it to imagine a young Rowan Atkinson with a Brown Thomas accent, a fogeyish Trinity dropout who spends his days in the ancestral home outside Dublin watching old movies and drinking his way through his late father’s cellar?

Quite why Charles Hythloday turned away from reality is never explained. An Irish education, no matter how expensive, seems an unlikely breeding ground for Brideshead types, though readers who manage to reach the end of these meandering 466 pages may infer in an occasional scrap of repressed memory the possible seeds of his madness.

Of course, Charles’s self-delusion is part of the joke. Everything he tells us comes filtered through his skewed (and usually drunken) take on the world. Thus recollections of a crazy chemist father who built his fortune on beauty products (his dying words were “Son ... the world is cruel. Always ... moisturise ...”) are presented as the norm, and a dipso mother who storms about “like a Valkyrie late for Rotary Club” merely flits in and out of his consciousness as an irritating noise. Any perception of tragedy is reserved for Charles’s obsession with the actress, Gene Tierney. He plans to write her biography, although parallels between her experiences and his own family life evade him to the end. So, too, does the mental agony of his actress sister, Bel, and of their Kosovan housekeeper’s shattered refugee family who have infiltrated the house.

Charles blames all such dysfunction on the cruel world outside, most especially on the Celtic Tiger whose rampages, he realises, are changing the landscape every time he looks. When a series of farcical setpieces fails to sort out the family finances - think Blackadder, men’s bloomers, explosions, duels, faked death etc - our narrator finds himself displaced by a radical theatre group and thrown into the New Ireland. Unsurprisingly, college pals with names like Pongo and Hoyland are unable to help. They, too, are lost in this post-modern society: “It’s like being in Caligula’s Rome, and everyone around you is having an orgy, and you’re the mug stuck looking after the horse.”

Instead, Charles is taken under the wing of Bel’s ex-boyfriend, Frank, a working-class rogue of little brain and a heart of gold. And thus, on the other side of the tracks, our bumbling, solipsistic fool of a narrator will gradually learn about Real Life, Human Values and, you’ve guessed it, Love.

At that point, the author makes a last-ditch attempt to insert some real psychological backbone into his Hythloday family dynamics. Bel and Charles’s brief confrontation with their memories is touching, but it comes too late. Like a corpsing comedian appealing to his audience for more time, the narrator has lost the plot.

If only, instead of puffing its size as “epic”, the publishers had edited this farce about Ireland (can it still be called “new”?) into shape. Then a character such as Laura, the insurance executive from the Holy Child Convent, Killiney, could stand out in glorious relief with her use of the word “like” and blissful ignorance of everything from antiques to Australia: “Imagine, Christmas on the beach! Wouldn’t that be mad!”

Like her, Irish society could provide a gallery of portraits both more interesting than Charles and more deserving of Murray’s sharp ear and mordant wit.

Perhaps his next novel might look more closely at the grotesque in the everyday rather than the Gothic.