The truth hit her quickly in the end. After a year of circling slowly the truth ambushed her and made her captive to its implications. "Something is not right," said the greatest middle distance runner of her time as she abandoned another big championship in tears.

Seven days ago, before Ireland had even rolled out of bed, Sonia O'Sullivan dispatched a field of hopefuls in the first round of the 1,500 metres and pronounced herself fit, well and happy. For the most part we bought it. Sonia bought it, too.

When she came in to the media area last Sunday night, after a lacklustre semi-final in which she finished fourth and looked tactically askew, running most of the last lap in the third lane from the inside, she explained everything by announcing that she'd looked up at the screen, seen she was going to qualify and eased off.

"What's the point in killing yourself," said the woman famous for never having seen a contest which she didn't want to win.

She lost the 1,500 metres final on Tuesday night and, perversely, the bumping controversy gave her a crutch to lean on. Still hyped, she came bounding off the track and gave a hugely upbeat interview to RTE television. She looked and sounded as cheery as a radio jingle.

She then had her celebrated argy-bargy with the silver and bronze medallists and came skipping through the press area, smiling broadly, walking fast and refusing to speak to anybody. Understandable. Sonia had a case for protest against Anita Weyermann, who barged and pushed. Regina Jacobs had a case for protest against Sonia, who grabbed her just as she was about to hit the deck.

Five minutes later, though, Sonia was back in the press area, talking up a storm. She'd felt fine, she'd been positioned well, she'd had a winning chance. She kept grinning all the while. Less understandable. She had run a race which was nine seconds outside her personal best, she had seen gold go to a time six seconds outside her best. She kept grinning.

Her determinedly upbeat performance to the media merely served to confirm the impression that Sonia was like one of those cartoon characters who runs over a cliff and keeps on running long before the fall starts.

Something about the cheery face was not right. Her words announced her best intentions. Her eyes were telling us that she was in trouble. In Atlanta, with all its searing pain, she had shown too much vulnerability. This week Sonia was keeping the lid pressed down hard right until the end.

After the 1,500 metres final, those close to her expressed the view that she came to Athens at about 70 or 80 per cent of capacity. The championships came about a month too early for her to do herself justice. There is solace in that thought.

After the mental battering which she has taken, however (for the second successive summer), a prolonged absence from the demands of competition may be what is needed.

There is a temptation, after the poignant events of Thursday night, to write Sonia O'Sullivan off for good, to smother her in best wishes and then consign her to the scrap heap. To do so would be premature. To do so would be to underestimate her resilience and her obsession.

This is a woman who went to the hallowed track academy of Villanova and insisted on doing things her way. This is the harum-scarum bundle of potential who nearly won Olympic gold in 1992 with a race which served early notice of her pending greatness.

For the rest of the grand prix season that summer she faced the bump and grind of jealous older runners. She asserted herself physically, most notably one night in France against Hassiba Boulmerka, and established her own aura. This is the woman who recovered from the crushing disappointment of Stuttgart and became world champion two summers later.

Certainly, this week, Sonia was the last person in Athens to admit that she was fooling herself. By Thursday evening, however, she was accepting the virtually incontrovertible evidence that there was something wrong with her. One suspects that her personal history is as much to blame for her reluctance in reaching that conclusion as anything else.

There is a story which the javelin thrower Terry McHugh told to a journalist some years back which explains much about the O'Sullivan psyche. At the European Championships in Split, in 1990, Sonia was distracting herself with a small computer game in which McHugh expressed an interest. Sonia had clocked up a score of about 5,000 points. McHugh borrowed the game and clocked up double Sonia's score. Sonia came back and put 15,000 on the clock.

McHugh borrowed the game again and got the record score up to 20,000. About 36 hours later, McHugh was summoned to Sonia's room and shown the machine with 150,000 points on the clock. He conceded defeat. That's Sonia: the woman who knows her personal best time just for running to the park where she does her training.

Personal history. Before Thursday night, Sonia O'Sullivan never conceded a defeat in her life. That obsessive need never to give in compounded the disaster of the Atlanta Games. When she most needed rest, Sonia was back on the circuit quickly, running herself into more trouble, culminating in the disaster of the grand prix final in Milan early last September.

Last winter Sonia spent time in Limerick undergoing a series of tests which revealed her to be run down like a flat battery. She spoke then of changing her attitude to training, of developing a new, less-taxing regime than that which she had adopted after the defeats at the hands of the Chinese four years ago in Stuttgart.

Rest and a new lighter training regime? Right ideas. Wrong woman. By early January Sonia was running hard races in the Australian sunshine and knuckling down for another gruelling year.

She is famous for skirting close to the perils of over-training. In the US, she works with her friend and neighbour Marcus O'Sullivan and her appetite shocks him sometimes. In Teddington, in London, she runs with the top Kenyan men in the stable of her agent Kim McDonald.

In the seasons since Stuttgart she has just continued to work harder and harder, expecting the reward to flow exponentially. In the past year that workload has taken its toll.

She went to the Palace Omnisports in Paris in early March this year and confirmed the impression that she was trying to force things, running a tactically-suspect race and finishing second in the 3,000 final to the rising Romanian star Gabriela Szabo.

Bitter disappointment followed at the World Cross Country championships in Turin in March. O'Sullivan, seemingly not confident of her ability over the closing stages, hit the lead within the first 500 metres, an unsustainable position and a naive one for an athlete of her greatness. She was swallowed up and finished ninth.

Ireland finished third overall in the team event that day and though later she stood and grinned with her bronze medal-winning team-mates, she looked absolutely desolate in the moments when she was left alone. Remarkably for one of the world's greatest athletes, she was in Turin without a coach of any sorts. Rudderless and struggling.

Back in Europe, she linked up, at the recommendation of John Treacy, with former English marathon coach and director of the London marathon Alan Storey. She carried on with her regular routine, basing herself in her house in Brwyn Maur, near her alma mater in Villanova, for the latter part of the spring, rounding of her American stint with a customary visit to the Prefontaine Games in Oregon in May.

Alan Storey's influence on her was welcome, but probably came too late to save her season. In the space of a few days in June she ran poor races in Paris and Sheffield and withdrew from the circuit altogether for the five-week period before the Athens championships.

She came to Athens last week with a lot of work under her belt, but not quite enough. What was needed, perhaps, was a reconstruction of her season.

Yet, in the aftermath of her defeat in the 1,500 metres final last Tuesday night, when she had escaped the press area and had time to think, she was quietly philosophical but not yet brutally realistic. She consigned the 1,500 metres to the scrap heap of experience, deeming it a necessary speed-training exercise to get a few 61 or 62-second laps under her belt before defending her 5,000 metres title. That sweet, consoling thought went AWOL on Thursday night.

Next season can be a quiet one for Sonia O'Sullivan. The calendar bears no event of greater significance than the European Championships in Budapest. Then, in 1999, it is back to the cycle of the big time: World Championships followed by the millenium Olympics.

She can definitely salvage something worthwhile from a career which has seen a brief blossoming and a lot of intense disappointment thereafter. Age will rob her of that devastating final 200-metres kick which made her the most formidable middle distance runner in the world in 1994 and 1995, but if health and outlook permit her to tap into that remarkable stamina once more, who knows what is possible over the longer distances.

One thing is for sure. She won't quit. She is an endless enigma. Somewhere inside her is a riddle which she is trying to solve, a definition of herself which she needs to be at peace with. In her greatest moments, that obsession was what made her so beautiful to watch? Her desire to win was so feral, so wild, so huge it created a magnetism.

She is too great an athlete to have had a prime of just two summers, but too obsessive a woman to lightly accept the consequences of the urinary tract infection which robbed her of two golds in Atlanta last summer.

"I can't accept that there are things I cannot do," she said before the Olympics last year. "I just think that if I work harder I can do anything."

In the saddest moments, it is that obsession brings her closest to self-destruction, but which if harnessed properly offers the best long-term hope of salvation.