Usually after a game, I can write about the issues surrounding what took place as soon as it's finished, or if I've been present, once I've got home.
At the very least, I can make notes, even if only in my head.
Yet well over an hour after the United game finished, I still have the shakes, although thankfully they've abated to the point where I can type.
I've done a lot of travelling this week, as well as more intensive writing than probably at any point in my life. It all culminated this weekend, in the fixture you love to win but loathe to lose.
Feeling exhausted, this match probably meant more to me than any in the league in recent memory (and I'm sure it was similar for a lot of others).
First, because of the unenviable run that defeat would have created, which would have seen Rafa judged on five games, not five years, over which time (first 200 in the league) the manager has won more games than either Ferguson or Wenger did, and indeed, Liverpool's two greatest managers, Shankly and Paisley. Indeed, Benítez is 27 wins better off than Ferguson over the first 200 fixtures.
(I know times have changed, but you still need to be top class to post 114 wins in your first 200 league matches.)
Second, because even thinking of challenging for the title would have been written off, causing even greater criticism and further sniping. Liverpool have a long season ahead, and this victory does not win any trophies; but it's a step in the right direction. It draws to an end a bad run of results, with one of the best possible in any given season.
Third, because a defeat would have further crushed confidence, and once you start sliding, it takes on a momentum of its own; just as winning becomes a habit, so does losing, or failing to win.
Fourth, because of the bile and unpleasant sarcasm from some of the press, some of which went more over the top than a Roy Keane tackle on Alfie Inge Haaland.
Fifth, the opposition. Enough said.
Sixth, Michael Owen. While I don't blame him choosing United over his alternatives (such as Hull), and bear him no personal ill-will, nothing hurts more than a former favourite coming back to haunt you; and the sight of him in a United shirt is not a pleasant one. He deserved more respect during his time at Anfield, but of course, no-one forced him to leave.
And finally seventh, because in the build-up to the game I was afforded the hospitality of the manager, and saw in his eyes how much success at Liverpool means to him.
Although of course I am not, I felt part of the team, part of the club, for that day.
From one very brief conversation between the two in my presence, I could see just how much this game meant to Rafa and Sammy Lee, and how unbelievably thorough their preparations were; nothing was going to distract them from the task ahead.
I'm now just a normal fan again (albeit one who writes books, blogs and columns about the club), but I got a taste of life at the sharp end. I saw the inner workings. And it came just days before the visit of United.
The fact is, United could have had 1,000 beach balls on the pitch and they'd never have scored with the form of Carragher and Agger (how wonderful that he's fit again - what a player!), or kept out Torres and N'Gog, whose finishes were inch-perfect.
Every Red was a giant (which is kinda ironic for a side lacking exceptional height).
And it was achieved without both Gerrard and Aquilani, who, in theory, are two of the main attacking threats at the club. Also, Torres wasn't even fully fit. What a player!
(And if Aquilani had wondered for even a split second what he had done by joining Liverpool, given the recent results and his own longer-than-expected injury - which can only make settling in harder - he will have discovered what the club is all about this weekend. I can only imagine the amazement he experienced. He must be champing at the bit now. We can't expect too much too soon, but his return to action could be timely.)
While losing this fixture, especially in such circumstances, would have been too painful to bear, in some ways the choice of match might have been the perfect tonic; the crowd can get restless more quickly if they think you should be spanking the opposition, and that is always difficult when you don't know where you next win is coming from.
And if you win, instead of a mere lift, you get a rocket boost. You can't get carried away, of course, but the belief can come surging back. That very thing happened when beating Real Madrid and United last March.
Liverpool showed last season, even without Gerrard some of the time, and Torres a lot of the time, that they were far better than the critics were now portraying.
Now that a massive Argentine weight has been lifted from his broad shoulders, Javier Mascherano, despite his late red card, was back to his very best. Daniel Agger showed what we've been missing. And Jamie Carragher was like a man possessed. Past his best? I'd dare anyone to suggest that to his face.
Any critic of Lucas or Aurelio should watch this game, and hold their hands up; irrespective of form, brought about by struggles with confidence or injuries, they showed that they have the ability to be in midfield. Both did so at Old Trafford last season, too.
People keep telling me that Lucas concedes too many free-kicks, but if you want to play a fast-pressing game, and get in people's faces, that will happen, even by accident, or from the opponent diving. The key is to worry the life out of them, and Scholes and Carrick could not handle him and Mascherano snapping at them.
When Mascherano was sent off in the 95th minute, it was him and Lucas chasing to close down van der Sar!
While Lucas was outstanding, Aurelio showed that now he's had a few games back in the side, he's back up to speed. He is such a cultured footballer, and needs to be judged in context (ie not when lacking match fitness).
Same for the (inscrutable) critics of N'Gog: 20-year-old kid, in on goal to seal the game in the biggest moment of his career by far, and as cool as a cucumber plucked from the freezer.
His remarkable goals-per-minute ratio continues, and with a strike that no-one can write off as anything less than vital. (How can a £1.5m youngster be a 'flop' when he scores goals as regularly as he does, albeit in limited time on the pitch?)
I hate singling out players when everyone has been so good, but Yossi Benayoun, who only twelve months ago critics, including Graeme Souness (who should know better), were saying "is never a Liverpool player", just played a supposedly world-class defence off the park. His jinking runs were mesmerising, his through-ball to Torres the pass of the season.
And for a "two-man team" ("one-man team" with Gerrard out?), it was a resounding riposte to the doubters out there. How does a "one-man" team beat United? Indeed, last season a "no man" team beat them.
One of the biggest changes? Luck. Liverpool were by far and away the better side, and deserved every inch of the victory, but unlike in some games this season, got the breaks when they needed them, be it Valencia hitting the bar or the possible red card for Carragher only a yellow. After the beach balls and the other howlers from referees this season, and all the injuries, it was nice to get the little slices of fortune.
And this time United didn't have that late, late luck (with unfathomable added minutes, and own goals) that saved them against City and Sunderland.
Finally, all credit to Arsene Wenger, for his defence of Rafa Benítez this week.
To prove I'm not simply pro-Benítez (simply pro-top-class managers), I said the same about Wenger last season, arguing with Arsenal fans who wanted him out; while they knew the Gunners far better than I ever could, you don't dispense with proven quality in the hot-seat when it starts going against you.
I hate knee-jerkism of any kind. Thinking has to be long-term, not short-term. Your entire squad could fall ill with swine flu, and cause you to lose five games; you'd still get no sympathy, if you were Liverpool (or Arsenal) manager.
Some people will never have what it takes to win the world's biggest trophies, or even simply win more than a poor percentage of games as a manager. (These are the qualifications of critics, though.)
Benítez and Wenger, with major league titles and in Rafa's case, a European Cup, certainly do.