Sir Alex Ferguson has been asking daily questions of his Manchester United players on the training ground and especially on the pitch for 25 years - and he will go on making those same demands until he leaves Old Trafford.
He is tough but everyone I know found him to be fair as well. As a player, you always felt you were on trial and had to prove to him every day that you were good enough to pull on that red shirt. This is one of the reasons he and Manchester United have been so successful.
If the manager wasn't at training when it started but then came down later, there was an extra charge of energy in the work because you were very aware the main man was watching.
He was there 95% of the time and wanted high-intensity training. He was very meticulous, watched his players like a hawk and set out exactly what he wanted from you and the team.
One of his great skills was to apply the right man-management technique to different characters and personalities, and he has dealt with plenty of those in his 25 years.
Of course everyone talks about the famous "hairdryer" when he would blast his players. I think I experienced that more than most because he regarded me as quite a laid-back character so he always wanted to push me that bit further.
I wasn't alone in getting that treatment. We used to have a laugh at the player who was getting it - but I can assure you it wasn't much to laugh about when you were on the receiving end.
Sir Alex came from a managerial era when you did tear strips off players, but he was also able to embrace the other side of the game. He was old school and yet modern. He moved with the times and continues to do so.
I think in this day and age the idea of a manager having been at a club for 25 years seems extraordinary to everybody, especially a club like Manchester United where everyone is under the microscope all the time. To survive and continue to be so incredibly successful is unbelievable and shows how good he is.
He hates losing at anything. He is a very sore loser and, at the level he operates at, that is exactly what you want in a manager. He absolutely detests losing whether it's a quiz the night before a game or a game of cards. I've seen him throw the cards across the table when he's lost.
For 25 years at United - and at Aberdeen before, of course - he has been able to cope with the pressures on himself but also help his players when they were suffering or we were going through a poor run.
I came from Middlesbrough as one of his big-money buys and didn't make the greatest start at United because we lost 2-0 in my first game and I gave away a penalty. Some said it took me a full season to adjust to life at Old Trafford but the supporters made me player of the year at the end of that campaign, so I must have done OK.
There were a few mistakes at the beginning, though, and we lost 5-1 at Manchester City not long after I arrived in a game people still talk about now. There was criticism flying about but it wasn't just me. We had other new players who were getting criticised and of course the manager was getting plenty himself, probably more than anyone.
But he was very good to us when the flak was flying. He told us it was time to batten down the hatches. He told us he knew where we were heading and we just had to stay loyal and true to ourselves and the other players. No matter how much stress he may have been under he never passed it on to us.
Everyone talks about the Nottingham Forest FA Cup tie in 1990 as a game where he was going to get the sack if we lost.
The winner from Mark Robins has often been picked out as the moment that saved Sir Alex's job but I have spoken to Sir Bobby Charlton and the chairman at the time, Martin Edwards, on occasions since and they state categorically that he would not have been sacked even if we had gone out of the cup.
They said he would not have been sacked because they had seen the work this man was doing away from the spotlight. He had revamped the whole of Manchester United, made it more professional.
Sir Bobby said he could see the manager was putting a youth policy in place and getting the right scouting network and this is what they were so impressed with.
Of course, we won at Forest, went on to win the FA Cup after beating Crystal Palace in a replay in the final and the success just went from there. The club was always going to keep faith with him and he has repaid that with year after year of incredible success.
He has never let the club stand still, moving players on and building new teams. He had foresight and a long-term view.
When he signed players it might not have been necessarily to put them straight into the team - he was willing to let them develop as Liverpool would do. He didn't just look at a couple of years ahead; he was looking several years down the line.
One of Sir Alex's other skills was to appoint the right coaches around him but he was always very astute tactically himself, and his knowledge was immense. He was very meticulous in preparation on the training ground and was particularly strong when it came to the European games.
Of course, we knew all about the Premier League but in Europe he would sit us down to watch videos, the way opposition teams played and the systems they used.
Sir Alex retains that same approach today and shows no sign of losing that hunger even after 25 years. He did not just bring success back to Manchester United, he then maintained it over such a long period.
That is so difficult to do and what marks him down as arguably the greatest manager of all time.
Gary Pallister was talking to BBC Sport's Phil McNulty.