It was the Americans I felt sorry for. They were a young couple on holiday, I imagined, and had bought seats in a box having read the almost universally ecstatic reviews of a new West End production, The Play What I Wrote.
Morecambe and Wise, to whom the evening is a sort of tribute, will probably not have been familiar to them, but, as one of the critics put it, this was an evening to cheer you up.
Mystified and straight-faced, they watched the play. Bewildered, they looked down at the stalls as the audience, with a few exceptions, rocked with unrestrained laughter. When, towards the end of the evening, Richard E Grant appeared, the couple registered mild amusement, but there is a limit to the pleasure to be derived from watching a moderately well-known actor making a fool of himself, and by the time the show closed, inevitably with "Bring me Sunshine", confusion had returned.
Was this irony? I imagined them asking each other. An example of the famous British sense of humour? Did the majority of the audience at the Wyndham's Theatre really, genuinely find the play funny?
They looked discomfited by the experience, and so were we in my party of three. There is something almost uniquely alienating about sitting stony-faced in a theatre while all around you appear to be having fun – a suspicion that somehow, without noticing, one has become a sneering ironist unable to enjoy the simple, human pleasure of laughter. Yet we, like the Americans, were there to be cheered up.
Comedy, at its best, is a celebration of life, and the innocent laughter of classic shows like Morecambe and Wise, Porridge or Dad's Army is something we have lost. The best humour of today – Chris Morris, South Park, The Larry Sanders Show, Steve Coogan – comes with the price-tag of an inbuilt sneer attached.
It worried me at first that it was we, the unlaughing ones, who had lost our innocence. Hamish McColl's and Sean Foley's moderately clever formula is to wrap up a night of nostalgia, in which they are comedy versions of a tribute band, in a self-referential plot which nods vaguely in the direction of postmodernist irony. Yet the result is an infection of memory. Jokes which I have remembered for 25 years are now delivered, outside the context of the characters we knew so well, and are revealed to be really rather lame.
Perhaps none of it matters. We had a bad night at the theatre. It happens. But what seems significant about The Play What I Wrote is not the writing or performances, but the praise lavished upon it, sometimes by grown-up, intelligent people.
Jokes like "I've just had a breakthrough," "I warned you about those prunes" are hailed as glories of English humour. A play in which an endlessly repeated running gag is about getting someone's name wrong – "Pug", "Pugh", "Take one" – is the subject of a learned dissertation by DJ Taylor in The Times Literary Supplement.
What on earth is going on here? Are we now so desperate for the innocent laugh, so pathetically anxious to return to the uncorrupted pleasures of childhood, that we hurry to see a collection of dire playground gags and tell ourselves that we are watching a masterpiece of comedy? Could it be that the critics who are encouraging you to spend £35 on a night of bad pantomime are motivated less by a sense of humour than by a desperate clinging to the past, a fretful nostalgia?
Towards the end of the evening, McColl and Foley discuss semi-humorously the role of the straight man in a double act. Separately, they work fine, they decide, but only when they are together does the comedy truly work. "We are funny," one says seriously to the other. It is the best joke of the evening.