That is why, even after dealing to the English a week ago, les Bleus made a point of keeping a lid on their post-match celebrations. Julien Bonnaire, the flanker who played out of his skin last week, clearly remembers the euphoria of the quarter-final win in Cardiff in 2007.
"But I also remember the disappointment of the way we played the following week in the semifinal against England," he said. "This time, we are determined it's not going to happen again."
Most Kiwis have difficulty understanding the emotional roller-coaster of the French XV. But they should rest assured that all French coaches have struggled with the same problem. The 1979 Bastille Day win at Eden Park, for instance, came only after a loss to Southland in the midweek game, and the 2-0 series win by Philippe Saint-Andre's team in 1994 was preceded by a loss to Canada. As assistant coach Emile Ntamack said this week, if he and his fellow French coaching staff knew exactly what it was that enabled the Tricolors suddenly to play above themselves, they would put it in a bottle and take it on tour with them.
France then face a double challenge in tonight's semifinal: they not only have to overcome an ebullient Welsh side, but they also have to win a victory over themselves. But while it is all very well to pull one game out of the bag by using internal conflict to motivate the players, as coach Marc Lievremont wisely observed early in the week, that conflict cannot be artificially maintained, especially against a Welsh team they have beaten 10 out of the last 13 times they have met.
If the French really want to be world-beaters, however, they have to show that they have more than just one killer-punch in their armoury.
Last week they demolished England because they were angry. Can they get angry again?
* Ian Borthwick writes for L'Equipe, Paris