The Premier League season was still in its infancy when Jose Mourinho filmed a charity "joke off" with the Liverpool comedian and supporter John Bishop, as part of a Channel 4 telethon for Stand Up To Cancer.
Bishop and the Manchester United manager would take it in turns to tell a joke and the first person to laugh lost that round. Yet the funniest moment remains unseen by most. "OK, a wild card," Mourinho tells Bishop. "When was the last time Liverpool won the league title?"
Mourinho can barely finish his sentence he is laughing so hard as Bishop feigns outrage.
A couple of prominent figures at United were recalling the episode this week ahead of Liverpool's visit to Old Trafford tomorrow afternoon, when a 10th successive victory in all competitions for Mourinho's side would carry them to within two points of their Merseyside rivals and rekindle hopes of a title charge that had seemed implausible just six weeks ago.
It is easy to forget now that there were plenty of players and staff at United who, with Louis van Gaal nearing the end at Old Trafford, were privately rooting for the appointment of Ryan Giggs over Mourinho. Giggs, many thought, understood United, their core values, ethos and spirit, in a way Mourinho could never do.
But those same people who have watched Mourinho gradually re-ignite United over the course of the past eight months are also the first to admit that they misjudged the Portuguese.
To fully appreciate the liberating effect Mourinho has had at Old Trafford, though, on mood, morale, training and, crucially, the playing style as well as on the wider outlook of a club whose identity had become muddied since Alex Ferguson retired in May 2013, it is necessary first to go back.
anaemic Under Van Gaal, players exasperated by the anaemic football had got to the stage of talking about openly defying the Dutchman's instructions and longed for international breaks to escape the mundanity and demoralising "trials by video analysis", when they would be crucified for mistakes or deviating from his doctrine.
Under the Dutchman's predecessor David Moyes, respect for the manager was never there. There was the extraordinary instance, as Moyes remonstrated with the fourth official during the wretched Champions League defeat at Olympiakos in 2014, of a player shouting in ear shot of the Scot: "Send him off, we'd be better off."
Contrast this to Mourinho's burgeoning relationship with players who, in some cases, increasingly like to think of themselves as his "disciples".
From being paralysed by fear of being singled out in painstaking detail in front of the rest of the group, United's players feel free to express themselves again. Mourinho often opts against going into the dressing-room after games. If there is a criticism, he will pick his time to make it. "He is very clever in his psychology," one source said.
The vastly improved football is perhaps no better illustrated than in the way the full-backs, particularly Antonio Valencia, are deployed, and the performances of a re-invigorated Ander Herrera. Mourinho and his staff ended the default setting of full-backs having to pass inside to the centre-half, instead pushing them higher upfield in support of wide players, who are no longer under repeat instruction to simply wait for the full-back to overlap.
Van Gaal's insistence on players taking a touch before shooting and waiting for glaring openings were banished. Training became varied, entertaining, fast paced, regular shooting exercises a staple. United are averaging 5.5 more shots per game compared to last term.
Players turn up for sponsor events after training no longer sullen but with a spring in their step.
"More than anything, you can see the players love training again," a source said. Two central midfielders are no longer told to stay behind the ball, something Moyes and Van Gaal advocated. Michael Carrick's increased deployment from mid-November onwards has liberated Paul Pogba and enabled Herrera to become more of a box-to-box player. No midfielder in the Premier League has made more interceptions than Herrera's 53.
"On an individual level, he's improved me a lot in giving the team balance," the Spaniard said of Mourinho. "I now think a lot more about the problems the team may have if we lose the ball and how I should be positioned the moment this happens."
It is not all serious. In fact, humour has been a key ingredient behind the turnaround and there are few more ardent practical jokers in the camp than Mourinho and his assistant, Rui Faria. Staff and players who have fallen asleep on flights in Mourinho's company have woken to discover stuff in their hair and mouth and that the whole comic process has been photographed or filmed. Coaches' belongings are regularly hidden from each other.
Devotion to Mourinho among his closest lieutenants is clear. They often will not enter the canteen at meal times until he has appeared. It works both ways. Mourinho gave up his seat in business class on the flights to and from China for the club's pre-season tour to sit with his staff in economy. On European flights, he insists on sitting behind the players in a show of respect.
With his family still in London, Mourinho feels he has seldom been able to dedicate so much time to his job.
He has relaxed Van Gaal's insistence on the group all speaking English but will not tolerate cliques. He expects his staff to keep him fully informed of any problems in players' private lives. Preconceptions in the dressing room were challenged before Mourinho had even met the squad when he sent each player a text message so personal and perceptive that several consulted club staff to verify their authenticity.
There have been some darker moments, notably when he rebuked several players publicly and privately during a run of three consecutive defeats in September, but some think, in hindsight, he was testing their mental strength.
Certainly since the Fenerbahce defeat on November 3, when Mourinho questioned his players' focus and attitude, the improvement has been marked. United are unbeaten in 15. "You've got to show you're willing to go in the trenches with him", one source said.
Although quite shy, Mourinho, who seldom drinks, has a knack of making people feeling special. When Dimitar Berbatov recently asked to attend training, Mourinho made a point of seeking out the former United striker and welcomed the Bulgarian's plentiful questions. That goes for any visitor to Carrington.
One of Mourinho's big concerns before taking charge centred on the lack of natural leaders in United's squad, which is why he placed such importance on landing his two principal transfer targets, Zlatan Ibrahimovic and Paul Pogba. As well as injecting quality, he felt they would provide presence and personality, ease a burden on captain Wayne Rooney and help unlock the potential leaders in others whose confidence had been suppressed.
"They have filled that void left by big personalities such as Patrice Evra and Rio Ferdinand," one source said.
Staff, players and executives have been spellbound by Ibrahimovic's charisma. That supreme self-confidence is frequently interspersed with a sharp sense of humour that makes him eminently likeable. Ibrahimovic plays up to the public persona of himself with a permanent twinkle in his eye.
"He pretends he's God!" one staffer says affectionately. Asked to do something social media related for the club a few weeks back, Ibrahimovic replied, deadpan: "Why, do you want me to increase your following?"
One player recalls Ibrahimovic stripping down to the waist in pre-season, his six-pack rippling as he strode around the dressing-room, and thinking if this is how a 35-year-old looks after himself, others have no excuse.
Like Roy Keane, Ibrahimovic will not tolerate even the slightest slip of standards in training. Team-mates have been rebuked for under-hitting passes. "Sometimes he doesn't even need to say anything, you just get that look," one source said. "It's enough."
Mourinho was walking past the players' lounge at Old Trafford after a recent game when he spotted Ibrahimovic's wife, Helena Seger. "Thank you for keeping your man happy here," the manager told her. "It's really important."
The numbers only reaffirm his importance. No player in the Premier League has had more shots, efforts on target or touches in the opposition box this season than Ibrahimovic. Ibrahimovic and Pogba are in the top four for passes completed. Pogba, whom Mourinho talked about yesterday as having the "charisma, ambition and mentality" to be a future United captain, is fifth for dribbles.
galvanising Pogba's close friendship with Jesse Lingard from their time as academy graduates has had a galvanising effect and helped to bring a player such as Timothy Fosu-Mensah out of his shell, even though the young defender's chances have been limited.
Indeed, it is the treatment of players who have been on the periphery that provides perhaps the clearest indication of the subtle touch of Mourinho's man-management.
Marouane Fellaini came on as a substitute at Goodison Park early last month, conceded a penalty from which Everton claimed a late equaliser and was subsequently booed by United fans in the next game at home to Spurs. Mourinho backed Fellaini publicly but it was what he said in private that resonated, taking time to spell out specifically why he trusted the player. A few weeks later United activated an option to extend Fellaini's contract by another 12 months.
When Fellaini scored United's second goal in the 2-0 win against Hull City on Tuesday, the Belgian made a point of racing to Mourinho to celebrate. "How he has managed the situation with Felly is the best example I've ever seen of how to protect a footballer in difficult times," Herrera said.
Fellaini is not an isolated case. Phil Jones and Marcos Rojo thought they were on their way out of the club this month but Mourinho has coaxed a previously unseen performance level out of both. Bastian Schweinsteiger admired Mourinho's honesty in informing him right from the start that he would not figure in his plans and subsequent willingness to bend and bring him back into the fold.
The likes of Morgan Schneiderlin, who has now joined Everton, Memphis Depay and Ashley Young, while frustrated at not playing, were always made to feel part of the group.
It is an ongoing process but Mourinho's vision for United is certainly starting to take shape.