The hype built up by two stunning World Cup performances against New Zealand and England, plus last weekend's RBS 6 Nations demolition of Scotland had brought genuine reason for optimism among the Principality's 15-a-side fans.
Those hopes were cruelly ravaged by a rampant Irish pack in Dublin as Shane Byrne and Brian O'Driscoll led the way in a six-try romp.
Hansen, though, has urged his players to keep their nerve. There may be plenty of work to do before title contenders France visit the Millennium Stadium in a fortnight but the Kiwi still believes Wales are making significant progress.
"Test rugby is exactly that," he said. "You need self-belief and courage to go with your skills and it is vitally important the players keep that.
"For an hour we were outplayed and the scoreline was a fair reflection of the game as a whole, but there were some positives to weigh against the negatives.
"In very similar circumstances two years ago we lost by 50 points. This time we didn't cave in. We came back and probably dominated the game in the last 20 minutes."
During those encouraging latter stages, replacement Tom Shanklin darted in for two tries which at least gave the final scoreline a respectable look.
Up to that point, Wales had been second best in almost every department.
Dominated in every aspect of forward play, they conceded Byrne's opening score after just 58 seconds and then suffered the extra torment of having Irish skipper O'Driscoll rip them apart following his recovery a hamstring injury.
"It's a pity it didn't take another week to recover," lamented Hansen.
"Everybody knows he is an exceptional centre, probably the best player in his position in the world.
"He can run, pass, kick and his defence is like having another forward in the team. And if you don't commit him to the tackle he will be in there trying to pinch your ball. He was simply outstanding."
On paper at least, Wales have no chance of ending the 100% record France extended to two matches with their 25-0 win over Italy in Paris on Saturday.
But the same things were said when they played the All Blacks and eventual winners England in RWC and on both occasions the giants were badly shaken.
"We won't be going into the France game with our feet off the floor that's for sure," smiled Hansen.
"Sometimes it is a lot easier coming off a loss than it is when you have won. The players will probably be more focussed than they were last week.
"France's win over Italy was a classic example of a team just doing enough and it's exactly what they have tended to do down the years.
"You don't see them beat anyone by as much as they are capable of. They win the game, then have a bit of fun. That is what they did against Italy."