Leinster have scaled so many European mountains in recent years, it remains a fascination that they occasionally stumble over the odd pebble.
Connacht, stubbornly, remain the one team that seem to resemble a persistent stone in their collective boots, despite Leinster's status as multiple European champions.
Even when the teamsheets feature a swathe of players whose relative anonymity mimics the cast list of a Dublin city centre panto, the fixture retains a toxic taste of insurrection, a violent tilt at rugby's princes by the paupers.
Little wonder that Leinster wing Andrew Conway, one of a gaggle of stand-in players being unfurled for this expensive seasonal entertainment, says simply: "They're a side who can hurt you."
Back in October 2008, reigning league champions Leinster went west under Michael Cheika, but, despite parading messrs Contepomi, Horgan, Sexton, Elsom, van der Linde, O'Brien and Fitzgerald, they were squeezed out 19-18.
Cheika, as was his occasional wont, stormed back to Dublin without bequeathing a word from his lips having issued instructions to his players to do the same.
Instead, Connacht celebrated and their then coach Michael Bradley chirped that, despite his side being hosed in familiar fashion a week earlier – 58-0 by Cardiff – Leinster were a team he had "targeted" for a win.
Harmless stuff, really, but Cheika was infuriated then and he was still incensed fully 18 months later when he spoke about it before another of the biannual fixtures, despite the fact that his side were European champions.
They would win in Dublin, as they tend to do, but their exalted status didn't stop them succumbing embarrassingly in Galway again a month later, as even Brian O'Driscoll's appearance couldn't stem the bleeding in a 27-13 defeat.
Cheika blasted his side's poor attitude that night and, rightly or wrongly, it seemed as if the fixture between Irish rugby's haves and have-nots had developed a stirring element of resentment – from both sides of the divide.
Former Irish international hooker Bernard Jackman, whose career was re-energised by Connacht before his status as a champion and international was finessed by Leinster, measured this extra spice succinctly in his autobiography.
"Connacht always seem to play their best game of the whole year against us," he wrote. "Our lads hate going to Connacht. Leinster don't respect Connacht.
"We don't respect them because they will play well against us one week and then they will go out and roll over against someone else the following week.
"Even Munster fellas feel the same away about them. Connacht will take points off the Irish provinces, but gift points to everyone else."
Connacht were at it again this season, bouncing a feeble, weakened Leinster to all four corners of the Sportsgrounds two months ago in an extraordinary 34-6 success that mocked the westerners' lowly league status.
Of course, Connacht are also targeting Heineken Cup outings in recent times; a status Leinster fans regularly and volubly remind their counterparts would not be theirs, but for Joe Schmidt's side's back-to-back title wins.
Hence the whole Mike McCarthy transfer farrago – which made for a whole lot of good copy for us guys, if not a whole lot of sense for rugby folk – really managed to get under Leinster's skin even more.
Which makes it a pity that so many principal characters are absent this evening, having been cocooned in Carton House for two days this week with greater glories in mind than this inter-provincial face-off.
What the punters would have given for the opportunity to unveil a few panto-like tunes gently throwing jests at either McCarthy or, perhaps, Fionn Carr, a predecessor whose own move from west to east has – given Leinster's lack of faith in him on the bigger stage – failed dismally to prosper.
Or, as pointed out helpfully by Conway in relation to Paul O'Donohue and Dave McSharry, Leinster fans could occupy their time cajoling their Connacht rivals as to the nature of their heavily ex-Leinster quotient this evening.
Nonetheless, even without the leading stars, there should be enough grappling among the fringe players, with quite a few guys – the aforementioned Carr included – potentially fighting for their careers as contract talks loom.
And we, for one thing, will be most intrigued to see how the jousting between respective scrum-halves O'Donohue and John Cooney develops, as we have been led to believe that the pair are developing quite the competitive streak.
"Connacht have built on a good win against us earlier in the year and have pushed on with big results. We know that we have to really up our performance levels," says Conway.
"Looking at their defeat to Munster last weekend, they probably felt that it was a game which they could have, maybe should have, won. So, they'll be looking to come to the RDS and do a job on us.
"The thing about Connacht is that they have built a strong squad of players. Up front they're physical and abrasive and if we allow them the chance to dominate us, we'll be punished.
"I'm picking up a lot of experience and that was a big target for me at the start of the year. But, from a personal point of view, I don't feel as though I've hit my stride yet."
His side, reeling from their worst run of results in two-and-a-half years, need to get back in step here to put their season back on track.
Connacht have won just once in Dublin since 1985, so expect Leinster to maintain their unbeaten RDS record this term.
Leinster – A Conway; F McFadden, B Macken, A Goodman, F Carr, I Madigan, I Boss, H van der Merwe, A Dundon, M Bent, B Marshall, D Toner, R Ruddock, S Jennings (capt), J Murphy. Reps: S Cronin, J McGrath, M Ross, L Cullen, D Ryan, J Cooney, N Reid, A Byrne.
Connacht – R Henshaw, D Poolman, E Griffin, D McSharry, M Healy, D Parks, K Marmion, D Buckley, J Harris-Wright, N White (capt), M Swift, G Naoupu, A Browne, J O'Connor, E McKeon. Reps: E Reynecke, B Wilkinson, R Loughney, M Kearney, E Grace, P O'Donohoe, M Jarvis, T O'Halloran.
Ref – J Lacey (IRFU)
Leinster v Connacht,
Live, TG4, 7.15