Sir Alex Ferguson has revealed that in his view he only truly used the "hairdryer treatment" half a dozen times in 27 years in charge at Manchester United.
The phrase was coined by former United forward Mark Hughes to describe the times Ferguson verbally tore into his players at close quarters.
Over almost three decades at Old Trafford Ferguson experienced plenty of highs, including 13 Premier League titles and two European Cups, but of course it was not always a bed of roses. We couldn't help but wonder when those half a dozen occasions might have been...
Sticking the boot into Becks
Ferguson singled out David Beckham for criticism following an FA Cup defeat to Arsenal in 2003, and the Scot said in his autobiography that the England midfielder swore back at him. With a pile of football boots between him and Beckham, Ferguson kicked one of the boots which struck Beckham above his left eye.
"The next day the story was in the press," Ferguson recalled.
"In public an Alice band highlighted the damage inflicted by the boot. It was in those days that I told the board David had to go."
Beckham left United for Real Madrid that summer.
Manchester United 1-6 Manchester City
The players in red shirts who trudged off the pitch at the end of this game in October 2011 must have wished the ground would just open up and swallow them.
A couple of weeks before his 25th anniversary at Old Trafford, Ferguson oversaw United's biggest derby defeat since January 1926 - and it was just one goal short of equalling United's record home defeat, a 7-1 loss to Newcastle in September 1927.
Playing with 10 men following Jonny Evans' red card early in the second half, United capitulated in the dying stages as City scored three late goals. Ferguson described it as "our worst day ever" and said he was "shattered" and "embarrassed". You can imagine the dressing room wasn't a pleasant place to be afterwards.
United show their Spurs
Ferguson's "hairdryer" is clearly intimidating but it can also inspire. His teams were involved in some classic matches during the Premier League era, none more so, some fans would argue, than the epic 5-3 victory over Tottenham at White Hart Lane in September 2001.
Behind 3-0 at half-time, United staged an extraordinary comeback through goals from Andy Cole, Laurent Blanc, Ruud van Nistelrooy, Juan Sebastian Veron and Beckham.
In an interview with the club's official website Veron later revealed that a dressing down from Ferguson at the break inspired the fightback. He said: "I've never been involved in anything like it. El Mister, Ferguson, was not happy at half-time. He said we had no respect for the people. We scored five in the second half."
"Football. Bloody hell!"
Those were Ferguson's memorable words after United's injury-time comeback to win the 1999 Champions League final which completed a treble of league, FA Cup and European Cup. After a season playing some sublime football, United had saved arguably their worst performance of the campaign for the biggest stage of all and went into half-time 1-0 down at the Nou Camp against Bayern Munich.
Ferguson recalled he told the players at half-time: "The cup is only six feet away from you at the end of this day. If you lose, you can't even touch it."
It's not clear what tone that message was delivered in, but whatever went on in the dressing room had the desired effect as those late goals from Teddy Sheringham and Ole Gunnar Solskjaer completed one of football's most famous comebacks.
Red mist descends over shades of grey
Ferguson made his team swap shirts at half-time during a match at Southampton in 1996. Behind 3-0 at the break, United swapped their grey kit for a blue and white one with Ferguson claiming his players were unable to see each other on the pitch.
Recalling the incident in the Guardian a decade later, former Red Devils midfielder Lee Sharpe said: "The manager just stormed in and said: 'Get that kit off, you're getting changed'. Those were the first words he said at half-time."
United did improve in the second half and "won" that 45 minutes 1-0, losing 3-1 overall. The grey kit was never to be seen again.
Fergie Hammers title winners
Never one to allow standards to slip, Ferguson laid into his players moments before they went out to lift the Premier League trophy in 2007. United won the title with two games to spare but Ferguson became angry after a 1-0 loss at home to West Ham on the final day of the campaign.
In his autobiography My Decade, Wayne Rooney recalls what happened in the dressing room as they prepared to be presented as champions in front of a packed Old Trafford.
"Most sides would be celebrating in the dressing room, getting ready for the champagne and the photos," wrote Rooney.
"Not us. We're staring at the floor like school kids, the manager giving us the 'hairdryer'.
"After the rollicking it takes a while before everyone cheers up enough to put their Premier League-winning smiles back on."