IT was all down to Mo, Mac and Chrissie.

They are not a folk band from the sixties but rather three separate personalities who invited me to think.

I politely turned this invitation down as I had a column to write. But some of the residue from their comments has adhered to me in the same way as the white stuff from a Tunnock's snowball sticks to one's fingers. Or two's fingers if you are particularly messy.

First, Mo Farah said of his preparation for the London Marathon: "You can only give 110%; you can't do any more than that."

One suspects Mo did not win his Olympic golds in arithmetic, but one was desperate to add: "Hey Mo, if we are going down the 110% route, why can't you squeeze it up to 115%? Or even a soddin' gazillion trillion bajillion per cent?"

Then Chrissie Hynde - a popular singer, M'lud - pointed out that the new guitarist in her band was highly competitive. As this axeman (hey, I am down with the kids) is John McEnroe, this is akin to saying the Kardashians are not camera shy.

Mo and Mac are different in so many ways but they share that desire to win that separates the successful from the merely talented. And I don't mean the "kick your granny to win" theory. I mean "kick your granny, leave her homeless, cash in her pension and break up her wheelchair for parts for your bicycle" theory. Yup, that ruthless.

My brief interactions with top-class athletes across sports has led me gently by my large proboscis to two major conclusions.

The first is that they may be nice guys/gals off the court/pitch but they are desperate, straining beasts on it. There comes a moment in one's life when chasing a spherical object between a set of lines suddenly becomes a pursuit laden with a despair laced with pointlessness. But not to the greats.

This is not an intellectual deficit. Some top-class athletes are as smart as Stephen Hawking after he has munched a bowl of carrots. But they relentlessly chase, run, swivel and keep on keeping on. Ask Roger Federer why he keeps playing tennis and he will not be able to supply a coherent reason in any of the five languages he speaks.

He is worth more money than Croesus in the week the king of Lydia won the lottery rollover. He has four lovely kids, a wife he adores and has won 17 grand slams. So why does he keep running around gym halls after a yellow ball?

Most observers immediately reply that he loves it, so why should he stop?

But this brings me to point two. The other trait - apart from desire - that separates the greats from the rest is the ability to endure pain. They love the very thing that hurts them. Like being a football fan, but with millions in earnings.

A pertinent example of this is Tyler Hamilton, the cyclist. In 2002 he crashed in the Giro d'Italia and fractured his shoulder, but he continued, grinding his teeth in pain. He finished second after three weeks of riding but needed 11 teeth recapped. In 2003, he broke his collarbone in the Tour de France but used the grinding-the-teeth technique to finish the race.

Now cynics might point out that cyclists are on so many drugs they make Keith Richards in his heyday look abstemious. But cyclists know how to withstand pain. They share this characteristic with racket players, runners, footballers, rowers, swimmers . . .

Top-class sport is a veritable pain game that should be refereed by the Marquis de Sade. One must refine technique, become psychologically strong and become amazingly, even freakishly, fit. Yet it all counts for nothing if the desire and the ability to overcome pain do not co-exist. Eventually, the body creaks and falls apart, even if the "winners" continue to win by beating up fellow veterans or finding a wandering granny to kick.

It is all about the days in the sun for them. They welcome the hurt, they embrace the pain when they have a shot at glory in their heydays. They face retirement with an existential dread.

They know this signals a death and the grieving can continue for the rest of their days, breathing in the atmosphere of the top events while condemned to being an observer rather than a participant.

Their ego demands much more. But how can it be satisfied? One solution is to play guitar with Chrissie Hynde. But my advice to the truly self-obsessed is to write a column.