I know a man, from Rathmines in Dublin, who spends the winter in Ireland with his aged mother and the rest of the year in Queensland. A retired airline employee, he gets cheap travel, which helps. But how easy is it to keep a foot in both camps?

After trekking for 32 hours door to door with two kids and 13 pieces of luggage, believe me, it does not feel like a global village. True, we're all watching the same movies, reading the same books, and choosing the same brand in the supermarket. Sure, phone calls are cheap (at this end anyway), emails and text messages keep you in constant touch and you can view the local shenanigans via your paper of choice on the Internet. But who has the time to keep their head in two places? And really, what's the point? How can you get the most out of where you are if you're still inhabiting a shadow world somewhere else?

For the first few weeks in Ireland I was translating everything into dollars and having fits at what everything cost. Back here, I've been splashing out on what would have previously seemed luxury items. But as I slowly readjust to Australian standards, I will cut my cloth to suit.

It's the same with services. From Ireland I rang a friend in Sydney, whose child needed hospital treatment. While I was pleased to know her son was recovering, I found myself tuning out of her long analysis of the deficiencies of the health system. The parlous Irish situation concerned me far more than the waiting times at Westmead. But now I find myself weighing in again, reading the papers closely to get up to speed on what's happening with the education system, tax, housing and all the other inescapable aspects of where you live.

Meanwhile, after only five weeks, Ireland is receding fast. I now only occasionally read the 'Irish Times' on the net. It was never the same for me anyway as holding the real thing. My friends still email regularly, but I'm prepared for the fall-off: by next year it'll be down to Christmas cards and the odd call when someone gets sentimental after a few pints and realises it's daytime in Oz. I hate those 8am calls, my friends high after a good night, me stressed out trying to get the kids to school, not exactly the best mood for the kind of rambling chats I used to love having over there. I do it myself in reverse: suddenly realise at midnight that it's lunchtime there. But instead of fanfare because I've called, my friend is distracted: the soccer is on in an hour, the toddler has wet himself, or there's someone coming for lunch.

But the main, inescapable reason for the decline in communication is that soon I will no longer know how the other half lives. Right now, I'm familiar with all the issues: work, family, health, romance, money, general yearnings and future prospects. This time next year there'll be huge gaps, which have to be laboriously filled in. 'No, not Alan, he only lasted a month, I can't stand him now. No I mean Ronan, he's gorgeous, we're going to Kinsale for the May bank holiday.' Never mind the boyfriends, I didn't even know there was a May bank holiday.

I often wonder about the emigrants of old. I've researched the stories of the 4,000 orphan girls sent out from Ireland during the Famine to be domestic servants and future wives for the rough colonists. Put up initially at the Hyde Park Barracks in Sydney, they whiled away the hours sewing bonnets and petticoats, and playing counter games. Few could even write home: their careful stitching has been wonderfully described as 'the handwriting of the illiterate.' They were between the ages of 14 and 18, totally alone and at the opposite end of the world, with no hope of return. Not an auspicious start, yet most made a go of it, and so far as their descendants can ascertain, they led reasonably satisfying and productive lives.

Was it easier, in a way, to have to cut off entirely? Far better, surely, than to suffer the fate of the Returned Yank. I knew one fairly typical case: the eldest of seven children, growing up in the forties, it was a foregone conclusion he would go to America. He became a salesman for an oil company, and with his natural charm, soon did very well. The company gave him certificates noting his achievements, and the dollars winged across the Atlantic to his family. He bought a house for his aged parents, generous gifts for all his nieces and nephews. He returned every few years for Christmas, embarrassingly loud in his Hawaiian shirts, hybrid accent and Yank phrases. He never married, instead staying in exotic-sounding motels at the company's expense.

Then one year, he failed to make his quota. Hell, he was over fifty, people didn't take to you the same way as when you were shiny and fresh and just off the boat. The axe fell suddenly, brutally: he was jobless, with no pension, no entitlements, and after all that moving around, virtually no friends. There was only one thing to do.

When he came back, he used to go down the pub and buy rounds just like before. Having grown up in Ennis, he joined the Claremen's Association in Dublin, but he didn't really know anyone there either. Someone got him a job as a clerk with an insurance company and he found a small bedsit nearby. His youngest sister was still at home and had her eye on the house now she was finally courting someone.

Some months later, he was charged with embezzling. Although his own needs were frugal, he had taken the money to keep up appearances in the pub, shouting his 'mates' the way a returned Yank is supposed to. He got off in the end, when another family member paid the debt.

There was never any question of his getting to live in the house he had bought, where the sister and her husband were by now ensconced. Broke and disgraced, he went into hospital for a minor operation and told his niece he wouldn't be seeing her again. Sure enough, he never recovered.

It's easy to emigrate when you're young. What's tough is knowing if and when to return.