Christmas is a time of hope. A time to set aside differences. To celebrate the renewal of the human spirit. And a time to avoid three groups of moaning gits: teetotal Christians, hipster atheists and people like me.

I'm obliged under the Grandparents Act of 1893 to remind you how much better Christmas was in the old days. For a start, Advent started on 1 December or thereabouts. Now every year a magical comet explodes across the mid-November sky like a giant dirty snowball. Fine. You want the comet, you'll have to put up with what it's dragging along in its wake: a vast gas cloud of moaning old people.

Sure, extend the Christmas season. But remember we're grandparents. See how long we can really make it feel. It's a tradition, part of a package that includes bread sauce, flatulence, the Pogues, uncomfortable new clothes, a kid in a corner permanently hunched over something that beeps, and the depressing annual epiphany that there was an awful lot of padding in the Morecambe and Wise Show.

Beware, young people. Don't watch too many Christmas adverts, or you will turn into your gran. She's there, wittering away on the sofa. You can't hear everything she's mumbling, but the executive summary is: "Is this really what we need to get in for a 48-hour family lockdown? Frozen laminated pork on a stick? A video game featuring a stubbly psychopath? A telephone with a camera in it? A camera with a telephone in it? What's this got to do with Christmas? Eh? What has this? Got to do? With Christmas?"

So you sigh heavily and ask her if she fancies a Baileys, then realise that it's only the first week in December and your gran's not actually there. It's just you and the voice in your head talking to the telly. So you set up a separate account in your head and start remonstrating with the voice, which remains calm and asks you if you fancy a Baileys. And your Verified Subconscious shouts: "I AM NOT MY GRAN! I AM NOT MOANING ABOUT CHRISTMAS!"

And you switch off the telly, and it all goes quiet inside your head. And you find yourself inexplicably craving a whiskey and cream-based liqueur, and you are Gran.

Hardcore Christians are pretty unbearable at Christmas, but usually much easier to avoid than your Gran. It's not just that they can maintain eye contact while explaining how Immaculate Conception works. They also feel obliged to point out that, while the Nativity is, of course, a holy and wonderful thing, Easter, with its centrepiece of betrayal, torture and crucifixion, is more spiritually rewarding.

I think on balance I'd rather be stuck in a lift with them, though, than with a bunch of hipster atheists. The type who think that faith is "disgusting" or "dangerously deluded". They bang on and on, like they're winning the Age of Enlightenment all over again, rather than pointlessly kicking the inert form of the Anglican church. "You do realise, don't you," they parp, "that the Greek word parthenos attached to Mary in the New Testament didn't mean virgin at all. It meant unmarried woman." This makes the story more, not less, believable. Dear stupid hipster atheists: shut up, you haven't got "issues around Christmas". Nobody has "issues around Christmas", not even the Literary Review.

This used to be a time when believers and atheists held a ceasefire; the centre ground was given over to the vast majority of people who held no firm convictions either way. Let's face it, it still is. I suspect we massively underestimate the level of agnosticism among churchgoers and God-deniers. The traditional agnostic version of the Christmas story – some sort of special baby born in a stable, vaguely symbolising hope for the human race if we could just get along with one another. Is that so bad a myth? The more atheists mock the Nativity as a fairy story, the more sense it makes. The more Christians sneer at Christmas as a vulgar secularised holiday with drinks, the better it sounds. Life's a wobbly conga of uncertainty anyway, with or without tinsel.

The media stokes a lot of factionalism these days. Moan and countermoan. Daily Mail readers sneering at houses ablaze with lights, and terrifying Urban Santas and radioactive reindeer. Sun readers sneering back about poncey killjoys with their bronze turkeys and repressed sexuality and their children named after tank engines.

Sadly, the People's Media is even worse. By now there'll be hate groups on Facebook called Don't Let Sharia Law Criminalise Our Puddings and No French Hens. As well as several thousand astroturfed PR campaigns aiming to get underperforming artists to Christmas No 1 on spurious moral grounds: "Come on Mungo Jerry fans – download Bunk-Up In The Stable now! Together we can make Louis Walsh have a tantrum in his Harry Potter pyjamas!"

Social networks. Social FRETworks more like. If you want to avoid Christmas moaning, stay away from Twitter. Swarming with neurotics and umbrage-seekers, Twitter is a whirling snowglobe of nark at the best of times. By now there'll be ironised bleating about how #stopmoaningaboutXmas has become a top trending topic. People will be getting the hump about how a cool meme has been hijacked by non-smartarses who actually do want moaners to give it a rest. And there'll be appalled fundamentalists moaning about Christ being replaced with X in a hashtag. All in an incoherent paranoid fog of sulk, the occasional shrill voice surfacing to complain that their brilliant one-liner about a reindeer called Fenton is being retweeted without acknowledgement.

Are we better or worse off than we used to be? Was Christmas Past really more fun, less fretful? Well, call me old-fashioned, but optimism these days is nowhere near as good as it used to be. Contemporary optimism is rubbish. This Advent's been clogged with finance and mathematics. Pessimistic Mathematics! Released, like swarms of angry bees, into our festive living rooms! The news now is just a rota of windswept hacks shouting numbers from a bleak eurozone plaza. Which in my day (who do you think you are kidding, Mrs Merkel?) we called Continental Europe, thanks very much and don't forget who won the war. Yeah, America and the Soviet Union. OK, forget who won the war, just remember the Festival of Britain and skiffle. OK, forget skiffle – it was bollocks.

As a paid-up member of Grandad's Army I say this: bah. Defer this Euro-humbug until January when we're all supposed to be depressed anyway. Come on, let's have a knees-up now, postpone the misery and guilt until 2012. I slipped the word "guilt" in there, obviously, because old baby boomer bastards got us into this mess. We cashed in the postwar settlement and the property boom and pissed it all up the wall like the bloody Rolling Stones.

The problem apparently is that although there's loads of wealth around, the poor haven't got much of it. So instead of saying "sorry, recession, it's all gone shitmungous, we're going to need that dodged tax/transport subsidy/bonus/PFI payment/share dividend/backhander BACK asap", we're rolling over to have our tummy tickled by George Bloody Osborne and he's got this slight lip curl and he's asking us who's a good dog, and confirming that we are a good dog.

Now they're predicting a return to Dickensian Economics. Londoners atomised, polarised and shuffled into a rich side and a poor side in an actual giant reality show. The Scrooges tucked up in gated communities and the Cratchits squashed into affordable poorhousing. We seem to be heading there quite quickly too. If some steampunk version of the Department for Work and Pensions had been around in Victorian England, Tiny Tim would have been up a chimney quick as you like, crutches or no crutches.

We're all a bit scared to look too far into the future: 2061 is unimaginable, but it's been 50 years since 1961 and I can tell you that half-century's gone past like a late express. By now I was expecting Christmas on the moon and hover slippers and proper time-travel, not just in my head.

Optimistic young people, there is a way to avoid having Christmas spoiled by creaking miserabilists, eg yours truly. Ask us what Christmas was really like 50 years ago. Unless we're lying through our shambolic teeth that now look like a mouthful of peanuts, we will tell you the truth: it's always been like this. I can definitely remember old people moaning. A lot. Probably telling us that in their day you were lucky if you got a walnut, never mind a toy gun. Still, 1961, pulling away from the 1950s which smelled of steam trains and wet wood and tripe and onions, into the 1960s which smelled of roll-on deodorant, coffee and plastic …

Now 50 years on we've got the same Queen, same Christmas speech. Same Bruce Forsyth, though with more hair these days. Of course your heart sinks when you see the headline "Strictly v Downton on Xmas Day!" But in 1961, the primetime slot was "Gunsmoke v The Black and White Minstrel Show". Remind your Gran about that.

Despite all the evidence dumped at our feet by the government and the media, demonstrating that we're useless and feckless and costly and doomed, we're not, OK? We're not. We'll come through the recession and there will be marvellous things happening after I'm dead. Maybe my grandchildren simply won't put up with the stupid way the world's organised any more.

So yeah. Baby in the stable. Hope springs eternal. Well it does. It bloody does. It's what keeps us going. Merry Christmas.