Bruised Jose is overdue temper tantrum
Absolute self-belief is a very rare thing and difficult to sustain in a sporting environment.
To get to the elite level you have to have talent and an amount of confidence but when you get there, everyone else has the same gift and then doubt sets in.
Only those with a singular strength of will, fired by any number of personal motivational factors, become consistent winners at the top level and Jose Mourinho has been in that club for 15 years.
He never had doubts about himself or his mission. He was put on the planet to become the greatest manager and for a while, he could argue that case with some justification. Not now.
His pale, wan face after N'Golo Kante belted home Chelsea's fourth at Stamford Bridge on Sunday betrayed the confusion felt by someone who believes he is always right being shown very clearly that the opposite is the case.
He wore the same, part baffled, part horrified and part humiliated expression in the final weeks of his second coming at Chelsea. The wheels were coming off around him and he didn't know what to do.
With Mourinho, his total trust in his own genius and ability to do off a football pitch what he could never do on it, is everything.
His ability to transmit confidence to players and their willingness to accept everything he says brought him a long way, with a plan which has always been heavy on organisation and defence.
It is unsurprising that a man who had no real career as a footballer would lean towards percentage football in management, even though he was exposed to the game at its most beautiful in Barcelona.
He learned his coaching basics in England and when he worked with Robson at the Nou Camp, he was given responsibility for defence in training and match preparation.
When Robson moved on, he stayed to work with Louis van Gaal. Is it any wonder his version of Manchester United doesn't look all that different from the Dutchman's?
When he eventually became a manager in his own right in Portugal, it was a devotion to defence which brought success.
He brought this with him to Chelsea, where he smothered teams and locked up his penalty area, relying on fast legs like Damien Duff and Arjen Robben to punish teams on the break.
It won him the title but not the undying affection of Roman Abramovich, who decided that if he was going to continue emptying bags of cash into Stamford Bridge, he might as well enjoy the football as well.
This is where the debate on pragmatism versus purity hits a wall. Mourinho brought success to Chelsea fans who loved him for winning football games regularly enough to win trophies.
That's the formula Ed Woodward coveted when he chose to go against the wishes of many at Old Trafford and it's the only set of circumstances which make Mourinho an acceptable manager for men like Bobby Charlton and Martin Edwards.
There is no wriggle room whatsoever and no time. Mourinho has a warehouse of baggage which reduces the tolerance level for his often noxious personality.
He is coming to the boil, steadily. He had a word in Antonio Conte's ear about an exuberant celebration of Chelsea's final goal and we all raised our eyes to the sky, remembering Mourinho, coat flapping and arms raised as he ran up the touchline in another era at Old Trafford.
His confidence is battered and he appears confused by the requirement that he observe United's tradition of attacking football - whatever that is.
There were many cold winter nights during the Ferguson regime when his teams fought grimly for results and parked the bus in games best forgotten.
But there were many other days when the machine hit high gear and that's what fans remember. That and the trophies.
Right now, it is difficult to see United finishing in the top four and he will have to rely on a decent Cup run, domestic or European, to sustain supporters and buy him some time to make more adjustments to his squad.
That's why the latest episode of the Manchester derby tomorrow night is so important to him.
Pep Guardiola is under a bit of pressure himself after an indifferent spell for Manchester City but he is viewing the League Cup as an encumbrance, rather than a possible lifeline.