‘Is anyone here even remotely shocked that Nigella Lawson has done cocaine?’ I asked. Everyone shook their heads. Well of course they did: it was the after-show drinks in the green room at a BBC studio. ‘So why is it being reported in the media as if it were some amazingly big deal?’

No one knew the answer to that one. Everyone present had either tried Class As or been to numerous parties where they were about the only ones there who hadn’t taken Class As. Yet here we were, gossiping about the latest revelations from the Nigella court case for all the world as if they mattered.

‘One Direction are infatuated with Nigella Lawson and paid her a million pounds to have a six-some with her, in a giant tub of her How To Eat classic pea risotto.’ That would be a good story.

‘Nigella has done so much charlie that she has developed a Daniella Westbrook-style mono-nostril, lost her sense of taste, and is now having to have a new septum built from Chinese baby extract.’ That would be tragic but grimly compulsive.

‘Nigella likes a spliff and occasionally does the odd line. But is ashamed at having done so.’ Sorry, that’s even worse than a non-story. It’s an anti-story, made even worse by mumsy newspaper columnists granting her absolution by noting that she’s sorry and she didn’t enjoy it, which apparently makes it all OK.

Does it? Really? And do the same rules apply to marital infidelity: ‘Sorry, darling, about that Kate Moss business, but you really needn’t worry — I loathed every moment’? Or murder? ‘My client wishes it to be noted in mitigation, your honour, that since the incident he has had sleepless nights and was so traumatised by his victim’s screams he fears he may never be able to use an axe again, not even to chop wood.’

This is just silly. If cocaine were as unenjoyable as celebrities are forced to profess it is once they’re caught out, no one would ever bother taking it, would they? ‘Cheeky line? ‘No thanks, mate. It’s demeaning, it’s unhealthy, it gives you no pleasure — then afterwards you feel nothing but deep remorse.’

Except that this has rarely been my experience. Sure cocaine turns you into a complete dickhead, makes you think of little else except where your next line is coming from, never gets you as high as you’d like, gets increasingly disappointing, encourages you to drink and smoke too much, ruins sex, gives you a horrid chemical gacky flavour at the back of your throat, encourages you to make nicey nice with scumbags. But suppose we were all sitting round at a party and someone pulled out a wrap and began chopping up some lines, would I participate? Hell, yes.

It’s the same with spliff, even more so, in fact, because unlike coke, a nice joint can be very sociable. Am I shocked at the suggestion that Nigella may have had the occasional puff with her daughter? Well, suppose she did — which she denies — so bloody what? I certainly wouldn’t smoke drugs with my own children — they’re far too young and I’d be livid if they dabbled with such things before they left school. But after that? I expect I’ll be pretty relaxed about it, not least because I’d much rather have my kids be open with me about such things than be furtive and get themselves into heaps of trouble.

A few years back, you’ll remember, on a visit to see Tony Blair at No. 10 Downing Street, Noel Gallagher horrified the world by declaring that taking drugs is as normal as having a cup of tea. Noel was right. Obviously there’s a time and a place for them: not, for example, at 4.30p.m. — that’s for Earl Grey. But suppose, say, you’re at a late-night party and there’s a quality DJ laying down some decent dance anthems, it would seem to me quite, quite wrong — rude, even — not to enhance the occasion with a dab of MDMA.

And while it’s not something I’ve done in quite a while, it strikes me as absurd to pretend that this sort of thing doesn’t go on all the time and that our culture is any the worse for it. It makes people happy; by and large it doesn’t do anyone any serious physical or mental harm. Certainly no more so than alcohol, which as we know is capable of making people behave quite appallingly and can wreck relationships and destroy families at least as effectively as any illicit drug addiction.

In the end it all comes down to dosage. A while ago, at a grand political dinner party, one of the guests — a very civilised gentleman with a double-barrelled name — declared that he’d held down a successful City career for a decade while simultaneously nurturing a recreational heroin habit. If the rest of the assembled company was shocked, I certainly wasn’t. When the entertainment of choice is, say, a decent claret, everyone knows that there are painful, undesirable consequences if you overdo it. Why does anyone imagine that different rules apply to ‘drugs’? It’s not as though people only wear their sensible hat with alcohol, but put on a stupid one for everything else. What would be the point? The purpose of all drugs, legal or illegal, is to engender pleasure, not misery — and the vast majority of users self-administer accordingly.

So that’s my Christmas message to you this year: eat, drink and be merry, by whatever means necessary. It’s nobody’s problem but your own.