If we still had a sliver of doubt, Alex Ferguson has been kind enough to remove it. He has told us, by the somewhat dismissive route of going on American public television, what it's all been about. Guess what? It's all been about Alex Ferguson.
When his great predecessor Matt Busby quit, he took an office down the corridor of the place which he had redeemed from a bomb site, but was bitterly reproached by his successor, Frank O'Farrell, for playing a round of golf with the players he had nourished – Bobby Charlton, Denis Law and Paddy Crerand.
Rightly or wrongly, O'Farrell felt he needed a little more of his own space and authority.
Now we can only speculate on the reaction of Ferguson's anointed one, David Moyes, when he was told – on the difficult Champions League front of Donetsk in the Ukraine – that his sponsor had casually reactivated the Wayne Rooney controversy, dismissed any possibility that he would take up crisis management reins again at Old Trafford and, by way of an afterthought, delivered a dreaded vote of confidence to a man plainly suffering from a degree of shock at the scale of his inherited challenge.
As the hype begins for Ferguson's second multi-million autobiography in 13 years, O'Farrell's old complaints about the huge and dominating presence at his shoulder are rendered rather quaint.
When O'Farrell was eventually summoned to the boardroom to hear his fate, he quipped: "Well, it's a nice day for an execution."
By sharp comparison, Ferguson blithely asserts the wisdom of his choice of Moyes, while handing out such tidbits as the overtures he received from Roman Abramovich 10 years ago, Gary Neville's rejection of a coaching job, the reassertion that Rooney, indeed, asked for a transfer on the last day of a title-winning season, and his certainty that David Beckham's football goose – at least in terms of performance – was cooked when he met the pop star he could not bring himself to name.
O'Farrell had to live under the shadow of a legend substantially burned away by serious personal injury at Munich and the effort required in building a third great team and winning the club's first European Cup.
Moyes' plight is the sharply different one of walking in the footsteps not of a man seeking the shadows, but one plainly happy to bask in the still potent and hugely saleable glory of a sensational career.
It hardly helps that Moyes is required to maintain that success, or at least a sense of its rapid return, against the daunting evidence that Ferguson's last great triumph in the Premier League is, by the day, looking ever more a direct result of his extraordinary ability to suspend the possibility of defeat.
This is a theory unlikely to be threatened by Ferguson's barn-storming march into a notional retirement.
Certainly there was little evidence that he might be reflecting at all deeply on any of the difficulties Moyes has inherited when he told his American interrogator: "I'm not interested in managing again or getting myself worked up about Manchester United results. You would be throwing your money down the drain if you put any on me coming back as manager.
"I made by decision. The timing was perfect. There is no way back for me now. I've got a new life. I want to go to the Kentucky Derby and the US Masters and the Melbourne Cup. I want to visit vineyards in Tuscany and France."
Yes, the timing was perfect – but for who? For Moyes, no doubt, there was no good or bad time to be appointed to the job that, we are told, Jose Mourinho pined for, and believed he had secured when landing his second Champions League title with Internazionale. However, in any scale of inherent difficulties, it could hardly be said that Moyes was installed in the most encouraging circumstances.
Ferguson states again, and quite unequivocally, that Rooney was in full blown rebellion, and nobody needs telling that Moyes faced the immediate challenge of restocking a fallow midfield.
Why isn't Ferguson getting worked up by United's shocking start to the season? Is he not at all fretful over the old saying in football that one measurement of a manager has to be applied to what he has left behind?
There was no sense of any of this in his American interview and you may well say that if any old football man had the right to move on with his life with absolute equanimity, it is surely Ferguson.
Equally, you can say that Moyes arrived at Old Trafford aware of the challenge before him and his need to swiftly install his own values.
What more could he really have expected from the man who bequeathed him the most dramatic story of sustained success in English football? Perhaps some vital help will come in that form which Ferguson says he most appreciated in the early, and notably tough, days at Manchester United.
That was always available behind the open door of the little office down the corridor. It was when Busby laid a hand on his successor's shoulder and said that he had to stay strong in his beliefs about how the game should be played and the values that he needed to impose on a club that for some years had lost it way.
Maybe Ferguson knows all of this – and maybe he thinks that he has plenty of time to support the man he hand-picked for the job he had made his own. Perhaps he, somewhat like Moyes, merely needs a little time to adapt.
The difference is, of course, he is selling another book based on a triumphant football life. Moyes, if Ferguson hadn't noticed, is fighting to stay alive.