Alex Ferguson's new book, Leading, is full of fascinating insights into a managerial career that spanned over four decades and saw him accumulate a glut of silverware.
Here are 14 things we learned from it.
Speaking publicly about the book, Ferguson reveals that he only had four genuine world class players during his time at Old Trafford. Treble winning captain Roy Keane was not one of them.
"If you read the papers or listen to the television commentators, we seem to be awash with 'world-class' footballers. In my book there are only two world-class players playing today: Lionel Messi and Cristiano Ronaldo.
"I don't mean to demean or criticise any of the great or very good footballers who played for me during my 26-year career at United, but there were only four who were world class: Cantona, Giggs, Ronaldo and Scholes.
Keane does however get a special mention.
"There were big influences like Bryan Robson, Roy Keane and Steve Bruce," he said. "They weren't the best footballers but they had wonderful desire and made sure they were the best players."
Ferguson's dedication to his craft is laid bare in punishing detail. A 'normal' day would see him arrive at the training ground at 7am and stay until 9pm; on Wednesdays, the finish time would be later as he would either be with the first team at a match, watching the reserves or scouting.
He also steadfastly refused to take holidays; his contract allowed him five weeks off a year, but it was not until he had passed 50 that he began taking just three of those.
The notion of an elopement to Scotland for a shotgun wedding might be a romantic one for many, but Ronaldo's sights were set less on Gretna Green and more on protecting his bank balance.
A financial consultant brought in by United to give advice to players on how to manage their funds suggested the laws in the country were more beneficial to husbands than elsewhere: "That prompted Cristiano Ronaldo to say that when the time came he would only get married in Scotland."
Ferguson's socialist principles are extolled throughout the book, yet there is little doubt that he remains of the champagne variety. In one passage he reveals his irritation with United's board over a proposed new deal for Wayne Rooney - which would double the striker's salary, and elevate him above Ferguson in United's pay scale.
"I did not think it fair that Rooney should earn twice what I made…We just agreed that no player should be paid more than me."
One of the more bizarre habits revealed by Ferguson was his insistence on vigorously rubbing his face moments before appearing in front of the media.
This was the suggestion of Paul Doherty, the head of sports for Granada TV, "so that I appeared bright and cheery and did not display a hint of tension."
Not a staggering revelation, perhaps, but Ferguson goes some way to justifying his backing for a group of owners who remain largely loathed by United's supporters following their leveraged buy-out of the club. His support was based, so he says, on the basis that "they did not come barreling in with all guns blazing".
Perhaps more importantly, "they never said 'no' or refused to do something that I cared about."
Always a stickler for detail, one of Ferguson's pre-match perambulations around City's then-home of Maine Road alerted him to the fact that the groundsman had brought in the touchlines several yards in a bid to stymie United's wide players.
"I complained to the referee, got them to widen the pitch and we thrashed City 3-0."
The process of negotiating with Tottenham's notoriously tough paymaster Daniel Levy on transfer deadline day is likened to being "nailed to a flagpole".
The deal in question, the signing of Dimitar Bebatov in 2009, takes several energy-sapping turns, with Levy throwing several curve balls in United's direction - from suddenly inflated transfer fees, to demands to sign the striker Fraizer Campbell on loan. Eventually the deal is done with seconds to go until the midnight deadline.
"That whole experience was more painful than my hip replacement," Ferguson suggests.
Ferguson's account of how they persuaded David Beckham - then based in east London and courted by Tottenham - that his future lay at Old Trafford is instructive.
The club sent the family United kits; the youngster was invited into the first team dressing room when they were playing in London; and Ferguson went out of his way to court his family, in particular his United-mad father. The hard work paid off.
Ferguson recalls, with some ruefulness, the list of players United failed to land.
Didier Drogba (pictured) was well liked but deemed too expensive at £25m; Thomas Muller was scouted as a 10-year-old while he was playing for a German amateur club, and a deal pondered before Bayern Munich scooped him up; Brazilian Ronaldo's move was thwarted by a failed work permit application; a 16-year-old Robin van Persie's possible transfer was scuppered by a touchline temper tantrum which convinced United's scout, Jim Ryan, that United should steer clear; and as late as 2011, a deal for Raphael Varane was almost on the table - with Ferguson on a train from London to Lille - before Zinedine Zidane snaffled him from under the club's noses and signed him for Real Madrid.
The image of Ferguson as a belligerent tyrant might still dominate English football's collective consciousness, but he is not entirely obstinate.
There are plenty of occasions in which he expresses deep regret in the book: giving a ferocious dressing-down to Mark McGhee for daring to celebrate Aberdeen's European Cup Winners' Cup win over Real Madrid in 1983; telling Jaap Stam (pictured above) he was being sold to Lazio in a petrol station ("a venue that probably did not make things easier for either of us"); and, most painfully, selling his son Darren to Wolves, an act which he says still has not been forgiven by his wife, Cathy.
Ferguson makes no bones about his autocratic approach to working at United. "I was always very careful that my control was not usurped," he writes, with icy assurance. "That explains why I sold players who tried to undermine my control… everyone is disposable."
No names are mentioned, but it is hard not to read that passage without images of Roy Keane, Ruud van Nistelrooy and others flashing before your eyes.
Ferguson's admiration for the Portuguese who served as his assistant on two separate occasions, from 2002 to 2003 and 2004 to 2008, is undisguised.
Players who moan at his exacting training sessions are given short thrift, it is he who is given credit for the memorable Champions League semi-final over Barcelona in 2008 (thanks to a practice drill involving players standing on carefully-placed mats) and it is he who Ferguson wanted to anoint as his successor.
On two separate occasions in the book Ferguson says Queiroz could have been his replacement only for him to decide to join Real Madrid and then Portugal ("a bad decision that turned into a disaster for him").
Ferguson does not pretend that Moyes was first choice as his successor when the death of his wife's sister prompted him to retire in 2013.
He details a meeting with Pep Guardiola the previous year where he had been unable to "make him any direct proposal because retirement was not on my agenda at that point"; while Jose Mourinho, Carlo Ancelotti, Jurgen Klopp and Louis van Gaal were all committed to other jobs.
It may have seemed as if there was nothing more intimidating than preparing for a private audience with Manchester United manager Alex Ferguson, yet the figure who offered me his hand in friendship was anything but the tyrant many warned I may be confronted with.
Alex Ferguson pulled off one of the great deals of his legendary career after Manchester United handed Wayne Rooney a mega-money contract in 2010 - as he ensured he got an even bigger pay rise than his star striker.