It wasn't until I went to the toilet in that bar in Killarney that I realised what was going on. Up until then I'd figured I was in a pub full of locals, the types who would come here every week to listen to "trad" music and sink pints of Guinness and chat with their mates and just be all Irish.
And then I went into the toilets, where the music wasn't so loud, and all I could hear was the accents. American accents. Everyone had one. Brash, noisy, American accents. Suddenly it all made sense. This wasn't a pub full of Irish people at all. It was a pub full of wannabe Irish people.
See, Americans love claiming their heritage. "Oh, I'm Italian," you'll hear some guy with the broadest New York accent you've ever heard say. "I'm Irish," says the blond-haired girl in the Syracuse jumper.
Americans seem to be obsessed with where their families came from, which is why it makes sense that they would want to travel to get in closer touch with those roots. And they do. Though you'll see American heritage-chasers around the world, in countries as far flung as Korea, or China, or Ethiopia, the nation you're most likely to find them is Ireland. There are 36 million Americans who claim Irish heritage – just ask them – and most seem to be in Killarney or Dublin at any given moment.
What's the attraction? It's not just the Guinness. It's the attachment, I guess, to personal history, the feeling that you belong in this place even if you no longer really do, the chance to give your life a bit more of a story, to see what it could have been like if things had taken a slightly different turn and your great-grandparents had never jumped on a boat.
Australians don't seem quite as obsessed with their heritage. We're a nation of immigrants as well, but you'll never hear anyone tell you they're "Irish-Australian". I never say, "Oh, I'm Scottish." I'm not. I'm an Australian with a red beard. We just don't hold that personal history as closely as Americans do.
Hence, I guess, heritage tourism has never been that big a deal for Australians. There aren't great crowds of us in Killarney pubs seeing where it all began. We do visit the UK, but that's more to "do the London thing", to live and work somewhere else, anywhere else, than to get in touch with the mother country.
However, things might just be changing. A survey that the company Wotif did a few months ago found that 67 per cent of Australians from a migrant background had already travelled back to their family's country of origin. That's a pretty large number.
And that's only people who would regard themselves as having an immigrant background – there are plenty more of us whose family history stretches around the world, who would choose to travel back to Ireland or Scotland or somewhere similar to see where our families came from way back when, but who wouldn't describe ourselves as immigrants. The desire to physically trace our personal histories is clearly growing – and it is, after all, one of the best reasons there is to travel.
I've done the heritage tourism thing. Despite the fact I'm not "Scottish-Australian", I've been to Scotland to see where it all began for the Groundwaters. I haven't made it as far as the Orkney Islands, which is apparently pretty much the only place in the world where you, as a Groundwater, can tell people your name and they won't immediately ask you to repeat yourself, but I have lived in Morayshire, in the north of mainland Scotland, as a way of getting in touch with more recent familial roots.
It's a strange feeling, going back to the place where so many of your family members once lived. Everything feels vaguely familiar, despite the fact you've never been there before. It all feels right and normal, even though it's technically pretty foreign. I feel 100 per cent comfortable in Scotland. I might not sound like everyone else, but I look like them. People stop me on the street and ask for directions all the time.
Some travellers go deep into the family heritage when they're visiting these places, looking for old houses where their great-grandparents once lived, trying to find gravestones in old cemeteries, tracking down long-lost relatives.
My trips have never been like that. For me it's more about atmosphere than anything else. It's just taking in that weird feeling of familiarity in a place you've never visited before. It adds an extra dimension to what's already a great travel experience.
So to Australian travellers I would say, make like the Yanks. Dig up some family heritage, regardless of how distant, and own it. You don't have to go around claiming to be Vietnamese-Australian or saying, "I'm Irish." But when it comes to planning a holiday, head to somewhere with family significance.
There's no need to engage in a detailed tracing of roots. You don't even have to research it at all. Just go to the place your family once called home and soak it up. Hang out in bars and restaurants; talk to people; see the sights. You'll learn more about the world, more about your family, and more about yourself.
And, when you come home, you'll probably still call yourself "Australian".
Have you travelled to your family's country of origin? What was it like visiting?
See also: 12 of the biggest myths in travel