Alistair, Bobby and George were cracking open the beer cans as soon as the Translink train set off from Central Station. This was 8.30 on Saturday morning. Would they last the day? "No problem," said Alistair. As the train neared Dublin, Alistair, more animated now, was looking for a guide to the hotspots of the city.
Would Ulster win? "No problem," said Alistair. That was why the party was beginning so early.
The Northern invasion was by rail, road, and air; more than 30,000 people converging on Dublin for a day that will live long and sweetly in the memory. We in the trains were the lucky ones. Still only 9.30 and as we headed for Newry we could see the cars, buses and mini-buses bumper-to-bumper on the Dublin-Belfast road.
Connolly Station was like the Twelfth of July transferred to the Republic. An army of red and white decamped from the trains, took brief stock, sought directions for the south side, and marched benignly for Lansdowne Road, taking several comfort stops along the way.
And Dubliners, civil almost to a fault, warmly and generously welcomed them. At Toner's pub in Baggot Street the regulars paid no notice to a young man wearing a Red Hand of Ulster flag with crown atop, with a Union Jack in its corner, draped over a Glasgow Rangers jersey. "You'd never get a pint like this in Belfast," the loyalist said truthfully, if rather disloyally, as he sunk his Guinness.
Across the road in Foley's pub the GAA Ulster flag, yellow flag minus the crown, flew proudly. Perhaps Foley's got their sporting codes mixed up, but it didn't cause any offence to the Ulster rugby fans who had to act like prop forwards to get as far as the bar.
In the lounge of the Waterloo pub another fan was suffering culture shock. "Two pounds forty for a pint," he said in disbelief. "I'm glad I'm going home tonight. I couldn't afford this place."
As the Ulster supporters filed out of the pubs ahead of kick-off, with their funny red and white hats, red wigs, red and white flags, scarves and inflatable fingers, one wag had to observe: "Ah, it's only Galway over for a GAA match."
While the majority of fans down from Northern Ireland would have been of unionist or Protestant background, there were plenty of Catholics and nationalists from the North, and all over Ireland, there as well to lustily cheer on Ulster.
Another encountered example of culture shock was one supporter, dressed and painted from head to toe in red and white, playing the bagpipes, and playing, almost surreally, Amhran na bhFiann. People thought it a hoot, and nobody took offence.
Some DUP politicians - ahead of another expected acrimonious day in Stormont today - were warning that people shouldn't get carried away by the occasion. Don't expect the goodwill and good humour of the day to transfer to the more rumbustious business of politics.
Fair point, but rather curmudgeonly. This was an important day. First of all, Ulster won and won perhaps too well (the day didn't quite live up to the glory and tension of the semi-final in Ravenhill). And secondly, Ulster - all of its nine counties - and all of Ireland rallied totally behind the team. It was a day of wonder, celebration, and great joy. Who could knock it?
Lansdowne Road was amazing. David Trimble and Seamus Mallon came on the pitch to acknowledge the crowd. Perhaps conscious of their First Minister and Deputy First Ministerships, they were a tad too statesmanlike watching the game, unlike the Dungannon alickadoo Ken Maginnis a few seats from them, who enthusiastically and spiritedly entered into the drama of the day.
In the men's at half-time one unionist supporter wondered would Gerry Adams get carried away by the occasion. Mr Adams enjoyed the day and issued a statement congratulating Ulster, and noting that "the best team won".
Of course it was Ulster folk adapting the terrorist tactic of intimidation wot won it. Colomiers could with justification take a case to the European Court of Human Rights. How could any team cope in such a cauldron of passionate and delirious support?
Stephane Peysson, the Colomiers captain, blamed the ref and expressed unhappiness with some of his decisions. "I am very unhappy with the referee. It was a political result. The Irish team had to win. It was like playing against 17, not 15, out there," he complained. Of course Jean Luis Stephane was wrong. It was like playing against 45,00.
Clare Murphy writes from Belfast: Deafening cheers and a red and white sea greeted the Ulster rugby heroes for their proud homecoming outside Belfast City Hall. "This is something I will never forget," the team captain, David Humphreys, told the crowd.
After a fashionably late arrival from Dublin, at 1.45 p.m. the team transferred to an open-top bus for the short journey to the city-centre. The European Champions were visibly overjoyed by their first glimpse of the 5,000 people assembled to welcome them. Team members held the cup high. Front-row props rocked the bus, chanting tunes.
Taking to the specially-erected stage outside City Hall, the team belted out victory tunes. A boy perched precariously on a street sign punched the air to the beat of the familiar anthems. An emotional father held aloft his baby.
With a final salute, the team left the stage to chants of "Ulster, Ulster" and slowly the crowd began to disperse. Inside, the Lord Mayor, Mr David Alderdice, awaited the team for a civic reception.