Rugby coaches talk about the importance of starting everything from a good platform. It’s especially valuable advice when you’re taking a train, but it was nearly lost on the Canadian behind me on the 1.15 from Paddington to Cardiff.

He had been engaged in animated conversation with a man from Newport (the Welsh one) about the relative prospects of their teams. So when the man got off at his home stop, the Canadian first helped him with his luggage and then continued the conversation as they both headed for the station exit.

“Is he not going to Cardiff?” another passenger – still on board – wondered aloud, just as the man himself noticed something amiss and scrambled back on board, to a round of applause.

Irish fans will be hoping that his team are similarly disoriented when Joe Schmidt's men begin their World Cup against them in a few hours time. It's a game Ireland shouldn't lose, but among the green-shirted supporters in the Welsh capital on Friday evening was a Clare man who wouldn't hear of such complacency.

“You don’t win anything on presumption,” warned Brian Cunningham, from Ennis, sounding genuinely worried about an opposition better known for ice hockey. “You have to turn up, every time.”

As if to confirm that the Irish team had indeed turned up, he and his partner Denise had earlier watched their arrival at the Millennium Stadium for the "captain's run". And much as he had faith in Schmidt's judgment, Brian was worried about some selections. For example? "Earls," he said, sounding a bit sheepish, being a Munster man.

Brian and Denise were typical of many fans in Cardiff, in that they weren’t staying in the city, or even in an hotel. Declaring the prices “a complete rip-off”, they were instead bunking with friends.

The egg-shaped ball with which this game is played might as well be a golden egg for the next six weeks, but there were many stories circulating of attempts to kill the goose. “I know people who have gone to world cups everywhere, even New Zealand, and they’re put off by the prices here,” said Brian.

Not everyone was complaining, in fairness. Having a pint in O’Neill’s city centre pub were a quartet including Niall Tumelty and his father Tommy, who had two double rooms for two nights in a nice hotel beside the stadium for a total of £900.

Of course it turned out that they were canny Northerners, from Derry and had booked last Christmas. Their only gripe was that by the time they got around to flights, the ones from the North were sold out. “We had to go to Dublin.”

Then there was an octet of women nearby who, unusually, were here for the first two games, in Cardiff and London, and were planning a trip to Devon and Cornwall in between. Their secret was a camper van, booked even earlier – last October.

The biggest problem with the arrangement might be that the group includes Cliona Glendon from Dublin and Patricia Mayse from Kerry, who have another game on their minds this weekend.

The camper van might be a bit small by Sunday evening, although as both hinted insensitively, the losers could always turn to another member of the group for advice on coping: Maria Flynn from Mayo.