Sir Alex Ferguson's 25th anniversary at Manchester United is a remarkable achievement for a remarkable man and he has earned every plaudit he will receive.
I played under Alex as a manager for Scotland, faced him as a fiercely competitive opponent when I was captain of Liverpool and he was in charge at Old Trafford, then observed his great successes at close quarters as a pundit for the BBC. I have nothing other than total respect for him.
People often talk about two things that happened during the years mentioned above - his decision to leave me out of Scotland's 1986 World Cup squad to go to Mexico and the day I ended my analysis of a United defeat with the words "you can't win anything with kids".
This was made at the start of the 1995-96 season when United lost at Aston Villa after selling Paul Ince, Mark Hughes and Andrei Kanchelskis, a season they ended by winning the Premier League and FA Cup Double.
Some people have the perception that Alex and I fell out when he left me out of that World Cup squad. We never had a problem then and there has never been one since.
Whenever I see him he is always very friendly and communicative - 1986 was simply his opinion against mine and, of course, as Scotland manager he had the final say.
Alex was actually apologetic about it. When he told me I just said I thought he was wrong. He said he couldn't get everyone into a 22-man squad and he was going to go with Scotland-based players Willie Miller and Alex McLeish in my position.
I had just captained Liverpool's Double-winning team and thought it had been one of my best seasons. I felt that if I couldn't get into the squad there was something wrong. It was a difference of opinion but certainly not an argument.
As for me saying, "You can't win anything with kids", I suppose those words could have haunted me given the phenomenal success United enjoyed. Instead they made me and people still talk about it now.
Alex has never said it but I think he might have agreed with me to a certain extent - and some people have told me he used to say "you'll win nothing with kids" to his players to inspire them. So I suppose you could say I played my part in their success.
What you have to remember is that those "kids" were an exceptional bunch like David Beckham, Gary and Phil Neville, Paul Scholes and Ryan Giggs. And there was a lot of experience as well with Peter Schmeichel, Roy Keane, Gary Pallister, Steve Bruce and Eric Cantona. It was also the season Newcastle contrived to throw away a nine-point lead.
I only played under Alex a couple of times with Scotland. He had been very successful at Aberdeen, breaking up the Old Firm's domination. He was youngish in managerial terms and had taken over as Scotland boss from one of the older generation in Jock Stein.
Alex was enthusiastic, knew what he was doing and you instantly formed the impression that this was a manager you could play for. He could get the best out of players and that is the very basis of good, successful management.
Some people think Alex and they think volatility - volatility with journalists, volatility with referees. But, with his own players - as I learned with Scotland, he was 110% behind them and fostered an us-against-them attitude.
To stay in management for 25 years is some achievement, but to do it for that length of time at a club like Manchester United, where you are under such pressure to get results and attention is focused on you every day, shows the sort of man he is.
You have got to have the drive, hunger, motivation and desire to get up every day and get the best out of your players. At the start of every season you have to have all those things personally - and you also have to ensure your players have that as well.
He must have tremendous inner and mental strength to do what he does, as well as complete self-belief. He must still want it so badly that he can't walk away. Why should he while he is still winning Premier Leagues and taking United to Champions League finals?
It can be like a drug - but it is a drug that can wear you out. Alex announced his retirement a few years ago, then realised it was a mistake and carried on. He was still motivated and has never stepped back from meeting a challenge.
I had some great times at Liverpool but knew when I was coming towards the end. If I could have had the great times without the pressure it would have been perfect but I knew in my mind I was ready to go.
The pressure came with meeting the standards at Liverpool and every season was getting harder - but Alex has done this for 25 years at a club like Manchester United. It takes some doing and makes my admiration for him even greater.
You also need the nous and experience to keep producing winning teams. When United lost to Liverpool in the FA Cup fifth round in 2006 I really thought they were coming to the end of their successes. They were so bad it was embarrassing.
The Chelsea revolution was in full swing and you thought United's era of dominance may be coming to an end, not a conclusion anyone would reach lightly. And yet Ferguson rebuilt to win three successive titles in 2007, 2008 and 2009 and the Champions League against Chelsea in 2008. This ranks up with his greatest achievements.
When I captained Liverpool to the title in what turned out to be my last game in 1990, who would believe we would be sitting here 21 years later and they have not won it since?
Manchester United have dominated those years - and the towering presence throughout has been Sir Alex Ferguson.
Alan Hansen was talking to BBC Sport's Phil McNulty.