O'Driscoll defies the gods to survive armageddon
The first thing to understand about Saturday is it was subtle as a brick through plate glass. The second is that truly epic confrontations always are. When the smoke had lifted and the children were all accounted for, no one was talking about the ethereal stuff. Why would they? Leinster don't report for duty in leotards and pumps.
Their workplace is Armageddon.
If we judged the quarter-final to be one of the most physical games ever played, this reduced it to an episode of 'Jackanory'. It was too good to be true. If anything, it reasserted a sense that all that now links rugby to its past is the shape of the ball.
When the game was amateur, Saturday would have been seen out in some Leeson Street basement, hosing down hooch that tasted like engine oil.
Back then, the match was a 'Sesame Street' party compared to the nightlife. Remember the Sunday newspaper social columns and their pictures of tuxedoed heroes, brandishing pints like trophies, even when they'd been beaten out the gates of Lansdowne?
Unless you were missing a body part, you took the night by the neck and bullied it into dawn.
If you were as famous as Brian O'Driscoll is today, that meant being the recipient of some wonderful perks. For one, you didn't have to queue. The better clubs would even rope off a couch for you to entertain on. And, in exceptional cases, the engine oil might come compliments of the house.
You could then wind things up with a half-pounder, fries and onion rings in the 'Coffee Dock' before tumbling into the scratcher around daybreak, a great Cedar toppled by fatigue.
It was a grand time to be a player. We might have been rubbish, but we could reach Olympic A standard at dealing with the disappointment.
This is another world. Watching O'Driscoll trudge down the tunnel after Saturday's defeat of Toulouse, the thought struck that he was unlikely to be planning anything more demanding for a celebration than negotiating his own stairs.
The French came with an exuberantly muscular pack and they were quite brutal on him at times. Most teams are. The Irish captain plays with a carnivorous edge on the implicit understanding that he gives nothing he doesn't expect to receive back in spades.
"No guts, no glory," as Jamie Heaslip put it on Saturday night.
Remember how near the end of the England game in '09, O'Driscoll had taken so many hits it was like watching a mob poke a wounded dog with a stick? Yet, they never broke his spirit. Deep down, they always knew they wouldn't.
Maybe Saturday caught his greatness in microcosm. For much of the day, he must have been thinking how Friday would have been better spent sitting, over-dressed, somewhere in the general vicinity of Westminster Abbey than on a training pitch. I mean, how hard could it have been to get the day off? Even Elton John found a babysitter.
Anyway, why sweat the small stuff over a game of ball, given the gods are, clearly, laughing in your face?
When David Skrela's penalty bounced off the upright, then jack-knifed freakishly over O'Driscoll's shoulder into the grateful embrace of Florian Fritz, you had to feel that this was destined to be a blackguard day.
Then the great man was sent to the naughty step by Dave Pearson, for what the English referee considered "cynical play". Cynical? To the naked eye, it looked as if Louis Picamoles had pushed him towards the grounded Vincent Clerc, albeit from an offside position.
It was like getting jail on the back of a rumour.
Worse, O'Driscoll was actually limbering up on the touchline, seconds from re-entry, when Picamoles then loped in for what looked an ominously soft Toulouse try. This wasn't the Aviva he was standing in. It was the Alamo.
If the challenge against Leicester had been fundamentally one of will, this was more cerebral. Toulouse moved the ball with such urgency and sleight of hand, it was like trying to second-guess the flight path of starlings.
And they backed up all this needlework with a physicality that made mothers faint.
At 20-16 behind, Leinster looked in trouble. Bernard Jackman wrote a wonderful book, 'Blue Blood', last year in which he shone a light on the almost homicidal intensity of modern, professional rugby. Towards the end of his playing days, Jackman was getting concussed as frequently as a chronic asthmatic coughs.
His career effectively finished with Leinster's Heineken Cup semi-final defeat in Toulouse one year ago, a game that even this connoisseur of brutal combat seemed mildly startled by. Toulouse, wrote Jackman, "banged us up and broke us down".
Now, it seemed, they were midway through a reprise.
Their big men, the Servats, Johnstons and Albacetes went bouncing into tackles like tugboats caroming off one another in a category five hurricane. Their dancers, the Clercs, Medards and Poitrenauds were running deadly, surreptitious angles.
Then Guy Noves began evacuating his bench ... Dusautoir ... Jauzion ... Lamboley. It wasn't a break that Leinster needed now, but a human rights representative.
Yet Jonny Sexton's nerveless kicking had kept them in touch and, on the hour, O'Driscoll struck. His try came just when it seemed that endless phases of Leinster possession would lead only to another red, wrought iron gate.
Fergus McFadden was on as a blood sub at the time and, for three or four extraordinary minutes, he'd pummelled the Toulouse line with a ferocity that would have had David Attenborough getting back in the jeep.
Then, suddenly, O'Driscoll was eight yards out and dipping low. Vincent Clerc and Census Johnston made token efforts at playing bouncer, but they were trying to rope the wind.
The stadium convulsed to the din of tectonic shifting, for Leinster were not for turning now.
Heaven knows where the celebrations took them. The rest of us settled for muzak and a dark room.