Giggs confessed: "It's truly frightening. I've had a few down the years - the first hairdryer treatment came when I was 14 or 15.
"They we re genuinely fierce, but only because Sir Alex has this incredible will to win and doesn't like to see players not fulfilling their talent.
"He gets very frustrated, which is fair enough, but because I had it from an early age, especially when I tried things that didn't quite come off, I'd just shrug at him. The lads in the team now would not believe how he used to be, because he's mellowed a lot."
Even Roy Keane, it seems, can't hold a candle to Fergie in the rollicking stakes.
Giggs added: "The gaffer was definitely the worst. Seriously, you've never seen anything like it. Just ferocious. Keany was never that bad."