'God Save the Queen' bellowed out of the Aviva Stadium as the band performed the final rehearsals.
A group of early fans in green making their way down to Lansdowne Road seemed to freeze fractionally, as though electrocuted, and chuckled grimly.
"Game on lads," said one, rubbing his hands.
The same galvanising effect was later witnessed out on the pitch in a show of shock-and-awe tactics that spoke as much of the immense mysteries of psychology as much as it did of sheer sporting ability.
The visitors had arrived for a party. Many had tacked on the St Patrick's Day festivities as an opener to a hooley which would take in the match itself - a mere formality. With the real event being the securing of back-to-back Grand Slams and smashing of the world record with 19 successive test wins.
Temple Bar was heaving at 10am with English revellers enjoying the build-up.
But what they got was the sporting equivalent of a hard Brexit. They might have retained their silver, but amid the cold realities of the here and now, it seemed to do them precious little good. That the dream ended with England coach Eddie Jones sombrely shrugging on his cardigan spoke volumes.
The build-up could scarcely have been more tense, with the emotion of a minute's silence observed for the tragically heroic crew of Rescue 116. The stadium stood as one as Captain Dara Fitzpatrick and missing crew members Mark Duffy, Ciaran Smith and Paul Ormsby appeared on the big screens.
It was deeply affecting.
The anthems played amid teeming rain and an air of mutual deep respect with President Michael D Higgins in place - and then came the peculiar turn of events which saw a no man's land of nothingness descend due to the overrun of the France V Wales game in the Stade de France. It might have proved anti-climactic but instead seemed to whet the appetites.
Five minutes late, they were slip sliding all over the pitch from the get-go with play that was fast and furious. Johnny Sexton's penalty 10 minutes in set the tone. The visitors matched it shortly after, but with a muscular try from Iain Henderson, they were set never to recover.
Sexton stood like a fortress amid frequent attempts to take him down. 'The Fields of Athenry' rang out gloriously and the half finished at 10-3.
England tried to rally in the second half but it seemed strangely impossible against the invincible force of Peter O'Mahony and the wall of green. They played like they had never seen rain before - huddled, miserable and exhausted.
The constant targeting of Sexton saw captain Rory Best, his cheek gashed red in battle, appeal urgently to the ref. "I also have a responsibility to my team," he said.
Then 'The Fields of Athenry' lifted again and this time, it was not a battle cry. It was a celebration. The faces of the English players were frozen in disbelief as the game drew to a close. Yes, they had won the Six Nations but you're only as good as your last game.
Rory Best strolled the pitch with his three small children afterwards, in a touching moment as the lights went out for the presentation of the Six Nations trophy.
It was patently clear this championship win had no gloss.
"Big lessons to learn today," said England captain Dylan Hartley. "We set out to win the tournament and we've done that. Obviously disappointed not to win this final game because we had high hopes, we had high expectations of ourselves."
As lights dimmed and fireworks burst for the razzmatazz, the players could barely muster a smile as they went to collect their medals.
The visiting fans were philosophical as they flocked to the pub - to be greeted by the vista of TV screens showing the amateur Dubs setting their own record, unbeaten in two years.
So that's how it's done.