I've seen much head-scratching going on about the Guinness celebrations and Arthur's Day recently. Do people really have an emotional attachment to the guy who signed a lease on a brewery 250 years ago?

What if the entire series of events flops and all we're left with is a pint down the local with some out-of-date bunting? The thing is, if you make something for 250 years you learn to do it right. The celebrations are, of course, just a giant coordinated global ad campaign but they also serve as a reminder that for Ireland there is something more to the drink, to the brewery. We are in a long-term relationship and we Irish don't do divorce. As a free democracy, Ireland is younger than Guinness by some way. Guinness didn't really have the teething problems that we've had as a race and always presented a clever, reliable, consistent face to the world, both at home and abroad. Perhaps, in watching the massive successes of something which has grown from among us, there's a genetic predisposition towards loving the story of the little Irish brewer who could. We had brewery-side seats as they got way more things right than wrong, all the time pouring out the drink and providing social lubricant to any gathering of more than one person. For sure, Guinness has had its head turned by fads and fashion -- Guinness Light and Breo were big flops -- but each time there's a blip, the recovery mechanism is pretty straightforward. Go back to first principles. Sell the pint of plain.

Like all great Irish epics, there are plenty of naysayers. Some critics point to the fact that Guinness hasn't been Irish at a corporate level for a long time, that without Diageo it would have been small beer in the global market. The policies of the worker-family housing, free bottles and health benefits for the local Dublin workforce have been changed by a cut-throat approach to margins and jobs. Brewers aren't craftsmen now, they're input costs. Sales fluctuate, sometimes impervious to the quality of advertising being generated.

There's a strong anti-drinking lobby out there that thinks there's a cultural significance to the fact that a drink, a brand, an alcohol is so revered. Would we get so proud and excited about anything else? Drinking, fighting, sport and talking about all three is the caricature growing fat on the shrillness of the arguments. The smallest wine makers around the world celebrate their culture, place strict controls over where the grapes come from, and the artistry of the craft is elevated to social capital. They're proud of their drink. But we should be too.

The process is all around us. A bit of rain and sun falls on barley fields turning slowly gold in patchwork, and, as you drive around the country, you know some of those fields will become your local pub's Guinness. Small and big farmers alike provide the grain that gets steamed and rolled and roasted, blackening just enough to give the Guinness darkness. That peculiar warm smell hovers around the brewery lingers at the Phoenix Park, across Heuston Station welcoming the travelling hordes, is companion to the horse-traders of Smithfield, and in olden times on good days must have had the Kilmainham inmates salivating. A pint settles. This truth is told every night in every pub in Ireland.

Last year Diageo said they were keeping Guinness in Ireland. We should fight them if they don't.

The Guinness harp is the same Brian Boru harp, turned backwards, that has been used for centuries. Would a drinks company today even try to appropriate the national symbol without being screamed down? For years we'd be offended by off-hand comments from English footballers who denied Jack Charlton or Mick McCarthy qualified to coach Ireland by saying the only Irish in them was last night's Guinness. But when the best ad campaigns have an Irish element in them, it's time to enjoy the fact that Guinness does represent us. We've added some bits and pieces to the blend over the years, such as Riverdance and U2 and our writers and our bankers, but to millions -- nay, billions -- of people Guinness is Ireland abroad.

It's Ireland at home too. Imagine for a minute a world without Guinness. Apart from the thousands of families who've lived on income from the brewery and related industries for 250 years, the Guinness family are also responsible for St Stephen's Green, the Iveagh Gardens and Iveagh buildings. The renovated storehouse is consistently the top tourist attraction. Every small pub in the country becomes transformed by an afternoon pint. Without Guinness we'd be celebrated for our cows, or sheep, or worse. We could end up like Wales, famous for leeks. Guinness is good for us.

The brilliance of the company, apart from its core product, has been in its marketing. The iconic art produced by John Gilroy in the 30s and 40s was a step out of time. A toucan sitting on a weather vane, beautiful Technicolor beak and gleaming white breast contrasting with a settling pint perched on his beak. The more recent globalised modern ad campaigns implicate us in the world beyond the end of the canal that flows to St James's Gate but always reflects back there. It's a little beating heart on the south bank of the Liffey, funnelling pints of stout around the world. Pick one up in the Stag's Head, or Grogans, or Ryan's of Parkgate Street. Let it settle and enjoy. It's part of who we are. HQ

- Katie Byrne