Sir Alex Ferguson has revealed the secret that underpins his stellar career in football management - leave no room for self-doubt.
It is not a trait anyone tends to think of when discussing the Manchester United manager, whose side took another step towards a record 19th league title with their 3-1 win over Aston Villa on Tuesday.
Rightly or wrongly, Ferguson often leaves no room for manoeuvre when a decision has been made and rare are the times he corrects them. To some, such a dogmatic attitude can be seen as weakness. However, in one of the most high-pressured jobs anywhere, Ferguson insists it is the only way to be.
"I very seldom have self-doubt,'' said the United boss in an exclusive interview with ESPN. "The thing I always think about making a decision is not to have any doubts about it.
"Why go to your bed at night-time having doubts? Be clear. You must have clarity in your decision-making. What is right and what is wrong. To me it is black and white. I try to erase doubts.''
Such is Ferguson's public profile that he admits myths have grown up around him that get bigger as time goes on. There was a point when he was furious about such stories - such as the claim he used to go behind the stand at East Stirling to practise swearing.
However, his three sons are more laid-back and have urged their 69-year-old father to be the same. Some traits remain though, including the intense work ethic that he developed during his youth in Govan.
"Your character and work ethic doesn't change,'' he said. "It is part of you and I like to see it in my players.''
That DNA is one of the reasons Ferguson has been so successful. Yet clearly, with 11 championships and two European Cups among a trophy collection unmatched in the English game, there is no motivation to be gained from a fear of failure.
"It was with me when I was young,'' he said. "Every manager knows the name of the game. You have to be successful. That drives a lot of people on. Who wants to fail? Now I am integrated into this club, which brings a responsibility to win. That is more accurate than the fear of failure that was there in the early days.''
And, at an age when most men are trying to find ways of filling their days, Ferguson's ceaseless desire for more gets him out of bed every morning, occupying his mind to an extent there is simply no time for what has gone before.
"You can't dismiss the history of Manchester United,'' he said. "That was one of the things I wanted to bring back. That was the challenge. But I never think about what I have won. I don't have time for that.
"There is a certain vanity about it anyway. What has served me well over the years is keeping my feet on the ground. Humility is an important aspect of your life and should not be dismissed.''