You know the story about the underdog? Well, let's just say you should keep him out of a corner.
For Ireland, this weekend is a step back in time as they bid to block England's march to the Grand Slam.
Though last weekend's defeat to Wales scuppered any hopes of a Triple Crown, there's pride and the opportunity for players to stake claims on a World Cup berth up for grabs. Throw in the prospect of welcoming the high-flying English side to the Aviva Stadium for the first time and there's plenty of spice to tomorrow evening's game.
For Girvan Dempsey, the tormentor-in-chief in two of Ireland's most famous victories over their neighbours, this is a bitter-sweet time.
The transition from his playing days to his new life has been relatively smooth. The Terenure man is enjoying the Elite Player Development Officer role with his home province, which combines the desire to impart the skill and knowledge that he accrued over a 12-year professional career to the next generation of players.
He combines his primary role with that of assistant coach of the province's Under 20, 'A' and British & Irish Cup teams, so though not the same as playing, he readily admits, it's the next best thing.
But these international weekends revive the anxieties and the emotions like no other. Think of Twickenham in 2004. Or remember Croke Park in '07. His try-scoring heroics on both occasions were two of the great moments in modern Irish sport.
He smiles at the memories, but typically detaches himself from the plaudits. Those occasions, he insists, were the results of two outstanding team performances.
"I can remember kicking a ball up and down Terenure College as a youngster, weaving past no-one in particular and imagining scoring a try for Ireland in big games against England or the All Blacks. To fulfil that dream is something that I will always cherish.
"Growing up, England were always so dominant in world rugby circles, but Irish sides always had the feeling that they could up their performances in those one-off games. In those early days we would have fed off the underdog tag probably because we felt that we didn't receive a lot of credit from them.
"So by the time they had come back from winning the World Cup in 2003, there was an air of invincibility about them and it was great to get a victory against them."
He pinpoints the dramatic finish two years later as another significant milestone coming, as it did, with virtually the last throw of the dice in the dying moments by Shane Horgan.
"And then the next year we were into Croke Park and the emotion of that occasion was just ... It was just incredible."
The Dubliner is conscious of the need to look forward rather than back, particularly with such stern tests to come this year, but he believes that there are a number of factors which can help swing the pendulum back in Ireland's favour after a frustrating last couple of weeks.
"Firstly, there's the new stadium factor which will bring about its own special atmosphere. Then there's the historical Ireland-England rivalry which inspires Ireland to a new level.
"We have had some great days, but also some really tough ones too and there were lessons learned in both good and bad times. I think we can raise our game again this weekend against them."
A committed Dubliner, he draws on the memory of Croke Park '07 like it was something that occurred only yesterday. If there has been a singularly more historically relevant contest in Irish sport then that was only probably surpassed by the Grand Slam success two years ago.
The pressure of that week engulfed the squad and gripped the nation with everyone having an opinion. Talk of anthems and respect dominated the newspapers as the home of the GAA provided the most fitting of backdrops.
"We had come into that game having lost the first game in Croke Park against France, so there was a lot of frustration because it was a game that we shouldn't have let slip. Every time you picked up a newspaper or turned on the radio it was the lead story and there was no escaping it and Eddie O'Sullivan was conscious we weren't distracted by it in the build up.
"There were suggestions in some quarters that the English anthem wouldn't be respected, but the people of Ireland really rose to the occasion once more and all of the emotions really hit home for me at the anthems. Everyone waited with baited breath, but it passed without incident and by the time the Irish anthem came around something seemed to click and it was just a wonderful 80 minutes to be a part of."
His positive memories of Croke Park would grow even further as a result of that Heineken Cup semi-final against Munster two years later.
"If I'm honest, I still can't fully detach myself from the big games for Leinster or Ireland and I find that on the morning of games you still go through similar feelings because you know how the lads are feeling in camp and the amount of work they've put in," he revealed on the eve of tomorrow evening's encounter.
"That feeling will probably only leave me once the new generation of players comes through the system, but because I would have played with so many players at national and provincial levels and because you see the same faces every week, you still get caught up in the big games."
Thankfully, Dempsey's decision to retire last summer was done on his own terms with his body intact and he is enjoying working with the next batch of schools and club talent.
"There's very good talent out there," he says.
"The process of identifying players starts from Junior Cup level and we have been really impressed by the quality of the teams who are trying to play a fast game with ball in hand. That augurs well."
Inevitably, the visit of England, in an international cup final of sorts, sharpens the mind like no other side and he is positive about Irish chances.
"Ireland are going in the right direction and it will take time for us to get to the level we want to be at," he says.
"But you can never go against Ireland when our backs are to the wall and I would back an Ireland win, albeit narrowly."
For Ireland the time is now to unleash the dogs of war.