Throughout the history of European club rugby, Leinster have felt that they have been playing catch-up to Toulouse.
Leo Cullen lined up for the Blues against the Reds and Black during his playing career and, over the past seven years, has been a coach trying to out-fox the flamboyant Frenchmen.
For most of his career, Toulouse more than had Leinster's measure and doled out some big hammerings to the Irish province.
They'll meet in tournament action for the 13th time today. The tale of the tape has them locked together on six wins apiece over 25 years of rivalry.
There's one meeting in particular that Cullen remembers, the 33-6 Heineken Cup pool defeat in France in the year that he returned to Leinster from Leicester Tigers.
The gap between the two clubs felt massive then.
"Some of the battles we had with Toulouse, we got some very tough beatings, particularly away in those early years," Cullen acknowledged.
“That time it was, could you actually compete with these teams ever, really, because they had so much of that early success in the tournament.
“Then you manage to close the gap at different stages, when Leinster went on to win Europe for the first time.
"But if you think back to that time, if you’re stuck in that moment there, you’re thinking: ‘Jaypers, these guys are operating at a totally different level'.
“You think of the history of the tournament, they have been the team that we have always seemed to be trying to chase in many ways.
"It's no different now. They are still the team we are chasing because they are a proud club, great tradition, huge resources and all the rest. It's a great challenge for us.
"So here are now, we’d like to think the gap is a little closer. But we’ll see at 3pm."
Leinster last conquered Europe in 2018 and, although they got back to the final the following year, they lost to Saracens in Newcastle.
In 2020, Sarries knocked them out at quarter-final stage in the Aviva Stadium, and last year it was the La Rochelle of Jonno Gibbes and Ronan O'Gara who ended their journey at the semi-final stage.
Fast forward to today and the clubs meet at the Aviva Stadium for a place in the Champions Cup final with nine tournament wins between them.
Leinster, on four, after one behind the record holders, but they won their most recent semi-final meeting - in 2019, also at the Ballsbridge venue.
"There’s always a team coming, isn’t there," mused Cullen. "There’s somebody bubbling away somewhere that wants to get to the top again.
“That’s the thing that keeps you on your toes all the time because if you ease off for a second there’s someone coming to take your place.
"We found that ourselves. You get to the top of the mountain and then someone is ready to come and knock you off your perch because the reality is you’ve to start at the bottom again, and start climbing again the following season.
“We’re getting up towards the top and it’s getting very, very competitive now so for our guys they’ve done a huge amount of work to get this far, it’s about making sure it’s that final push now.
"In these type of games, you don’t get extra points for style. It’s about getting through to the next round and Toulouse have done that incredibly effectively.
"You peak too early and you think you’ve got the perfect performance in a quarter-final but where does that really serve you in a semi-final or final.
"Sometimes it’s just about getting through to the next round. That shows a different type of grittiness or whatever it is that they have."
