"I am surprised. I must admit it is something I never thought about for a moment - it has been frozen into the memory bank. I thought Sir Matt Busby was here forever. He started at the end of the war and went right through to winning the European Cup in 1968," said Sir Alex.
"The time span seems to be much longer than mine. Of course, there are emotional issues. He had to rebuild the team after Munich. There was so much emotion. I did not have that. That is the reason he seemed to have been here forever."
Comparisons between the legendary managers are easy to make: both are passionate disciplinarians with an unrivalled hunger and desire to succeed. They're both Scottish, too, though Sir Alex is keen to point out one major difference between him and his compatriot.
"Sir Matt was a lot calmer than me," he added. "We are different characters, with different personalities. Scottish people have a determination to do well no matter what. They travel. I came down here with the single objective of being successful.
"The most important piece of advice he gave me was not to read the press. It was great advice and I have not read it since.”
With such a landmark occasion so close, the boss could not resist looking back at his United career to date and some of his achievements at the helm.
The manager said: "Liverpool were the dominant team in the 1980s. That is what I looked at. That