COLIN JACKSON was chatting to his old friend and rival Mark McKoy earlier this month, when he suddenly began laughing. McKoy, naturally enough, enquired what he was finding so funny, to which Britain's world 110m hurdles gold medallist replied: "I can't believe you were Olympic champion." And began to laugh again.

Recalling the incident yesterday as he looked ahead to what he vows will be his last competitive season, the 32-year-old Welshman maintained that his former house-mate, who beat him to the 110m hurdles title at the 1992 Barcelona Games, had taken his remark in good heart.

"He knew exactly what I meant," Jackson said. "I just found it ridiculous that he was Olympic champion. I mean, for Christ's sake, he's only ever run 13.08..."

Jackson, of course, has run a lot faster than that on more occasions than he can remember in a top-class career which saw him established as an Olympic silver medallist by the age of 21. Indeed, he still holds the world record of 12.91sec, the time it took him to earn his first world title back in 1993.

But on that day in Barcelona, the man regarded as the world's foremost high hurdler fell apart in the final, finishing a catastrophic seventh. And for all the sportsmanship with which he embraced the surprise winner afterwards, the defeat has dwelt with him ever since.

Three years ago in Atlanta, Jackson's Olympic ambitions were dimmed by illness and injury, and after finishing out of the medals he contemplated giving up the sport. But after undergoing a long-delayed knee operation, and renewing his links with the coach who guided his early career, Malcolm Arnold, Jackson set about restoring his standing in the world of the high hurdles. After securing his fourth European title in 1998, he added world indoor and outdoor golds this year. There is nothing left for him to win. Except the Olympics.

He gave some indication of his determination to correct that omission yesterday, describing how he had rejected Arnold's suggestion that he compete in the European Indoor Championships next March in order to keep up his winning roll. He will only compete sparingly indoors, starting with the CGU Indoor Grand Prix at Birmingham on 20 February.

"I have only one focus for 2000, and that's the Olympics," he said. "If I don't come home with the gold, then that's life. But I'll be doing everything I can. My family are all pretty cool about it. They tell me not to get worried, not to pile more pressure on myself. But it's important that I win it.

"I could say to myself that I've had a tremendous career and I've got nothing else to prove. But why should I let myself off the hook? If you've got the credentials to do something, it's a terrible waste if you don't try."

Although Jackson also believes he has important credentials for a life beyond athletics - most obviously with an ambitious project to write and produce a hard-hitting television drama series which he believes is about to come to fruition - he is still impelled to explore the limits of his potential long after the two other dominant British figures of his era, Sally Gunnell and Linford Christie, have retired.

He reflected yesterday on the unhappy situation Christie now finds himself in - cleared by a British panel of doping charges, but virtually certain to see that decision reversed by the International Amateur Athletic Federation at a forthcoming arbitration where he has declined to defend himself.

"Hell, it's an awful position to be in for someone who has done so much for the sport, and who is still giving such a lot through coaching," Jackson said.

He has drawn away from his former business partner and training companion in recent years - the last time they spoke was a chance meeting during the Seville World Championships - but he views Christie's position with some sympathy.

"I'm not surprised he's decided not to go to the arbitration," Jackson said. "He doesn't plan to run any more, and he's happy that the British have cleared him. Not many people win against the IAAF - what's the point of going over to Monte Carlo and arguing with them?"

Thankfully, Jackson's life contains no such distracting dilemmas, other than the decision of who he should appoint as executive director to the project he has developed in partnership with his sister, the Brookside actress Susannah Packer. He has several production companies interested in developing the script which, he says with a grin, has got "violence, sex, language, the whole lot" - a British version of the Tom Cruise movie Jerry Maguire, drawing on Jackson's experience at Nuff Respect, the management agency he founded with Christie.

For now, however, there is only one pressing challenge. To express it in the terms of that which faced Maguire - "Show me the medal!"