On the morning of Sunday 29 March 1981, David Bedford, a world record-holder at 10,000m, woke up from a night out, on little sleep and rang Chris Brasher to ask if he could run in a race that he was organising that day.
A few hours later Bedford was making his way around the first ever edition of the Virgin Money London Marathon, part of a field of 6,700.
Thirty-seven years on, this Sunday (22) will see the next staging of the race, an event which has been given a five-star endorsement by European Athletics Running for All which guarantees participants the race has met the most stringent of safety and organisation checks.
Bedford will be here again. Not in singlet and shorts but as the international race director of a marathon which has accepted 47,000 starters.
At the front of the field will be some of the greatest athletes the sport has ever seen, from the brilliance of Eliud Kipchoge, Kenenisa Bekele, Mary Keitany and, of course, Mo Farah, who will be cheered on by the 750,000 home crowd every step of the way.
But behind the battle for possible world records, prize money and a place in history will be the extraordinary reason this marathon, and so many others around the world, are among the greatest spectacles in sport.
Simply, for all those 47,000, there is just nothing like it.
As BBC commentator Steve Cram said during last year's race: "It never fails to inspire you."
Bedford agrees. "When you look back over 37 years, that is a long time," said Bedford, speaking today to European Athletics.
"There has been changes, it keeps moving, it takes on more every year but that is the way you build things. Do not do anything silly at any one time, understand what the implications are if you can go a bit further next year, then do so.
"It is absolutely superb. You have spectators and people cheering on both sides. There is very little difference between the mentality of most of the people running and most of the people watching on the other side of the barriers.
"You see that interaction on the course. It is not just one way. It is a two-way interaction and the spirit you feel on the day is wonderful."
And, over these past 37 years, what is the one memory which stands out for Bedford?
"Michael Watson," he replies, without hesitation.
As he is talking, Watson himself is sitting in the room at the race HQ hotel in Tower Hill, London.
It was back in 1991 that Watson spent 40 days in a coma and had to have six brain operations after collapsing in the ring in a super-middleweight fight with Chris Eubank.
Incredibly, in 2003 he then completed the London Marathon over a period of six days and is back to reflect on that experience.
Bedford says: "It is easy, and I don't mean that in the easy sense, for people to make the task harder for themselves by putting on heavy outfits and things. But Michael Watson, it was made hard for him after the accident in the ring and that's true courage and true grit and for, my best memory."
On Sunday, the mass start launches at 10.00am and by mid-to-late afternoon, so many more stories will have emerged, so many more stories to be told, so many golden, glorious moments for those running as part of one of the best days of their lives.
The European Athletics Quality Road Race standards act as an assurance for road runners throughout Europe. They distinguish between races that respect the standards and those that haven’t sought certification or assessment. They form the foundation of Running for All, a strong recognisable brand for running activities throughout Europe.
More information on Running4All: