On August 18, just before noon, he pulled out of his heat, his Achilles tendon making even limping visibly painful, sending every Beijinger in view into the closest huddle to weep together. To weep, sad, shocked and bewildered.

China had till that moment been somewhat aloof from the Games venues. It had been hospitable, its volunteers at the ready with a smile and assistance, the stadiums designed to celebrate record-breaking feats. But it had been playing perfect host. It had not revealed itself beyond the superpower aspirations seen through architecture and urban infrastructure. Revelations of its frailties were certainly not on the agenda.

But as Liu went out, China showed emotion. The narrative of Liu’s special place has been told so often that it is a legend. By it, his victory in the 110m hurdles at Athens demolished myths about the limitations of Asian athleticism. It had given the Chinese a hero for his age, modern, global, with a sense of himself. And when he pulled out, it was not quite clear what hurt more: his personal absence or the failure to win that athletics medal.

In these extraordinary Games of Michael Phelps and Usain Bolt, of Indian breakthrough and of British ascent, of China’s likely long-term dominance of Olympic sports, Liu’s unexpected departure was possibly the most arresting moment of the 2008 Olympics. Liu, till that disconsolate appearance, had been everywhere in hoardings, write-ups, chatter. He himself had been little seen. And the more fanciful amongst us will see in that build-up a tragedy that maybe had to be.

But this was not about just Liu the athlete. The outbreak of emotions — grief, anger, perplexity, curiosity — asked the big Olympics question, what is the measure of a single medal?

In that moment, just for that moment, you could have suspected that China would have traded its entire, formidable haul for the prospect of having him on the 110m hurdles medals podium. Of course, only for that moment.

Then, the Chinese had 35 golds. By the time the Games closed tonight, it was 51 golds in a total of 100 medals. For the US, the corresponding numbers: 36, 110. (Before the Athens Games, China’s sports minister is said to have told the US Olympic committee chairman, “Don’t worry, we will not topple you. But we are making this effort.” Evidently the reassurance did not carry forward to Beijing.)

For China, sport has been a dominant form of self-assertion and of engaging with the rest of the world. But, remarkably, its state-controlled newspapers have been allowing criticism of the rigidity of the network of state sports schools.

Others, however, are looking to China, and wondering what lengths a country should go to acquire gold. Upon failing to win a medal in synchronised diving, the American team said their country had much to learn from China. They, the American divers, would have to return to the necessity of holding a job while training, while their Chinese competitors, gold medallists in this case, would be looked after by the state.

Is there, however, a way to assess individual feats? Is there a scale that shows the worth of an individual haul? To use a popular graphic, if Phelps had been a nation, at the end of the 2008 Olympics, he’d have been tenth in the medal tally. Of course, if he was your average 23-year-old, he would have been a guy with a goofy grin and a strange body.

Now he is a creature that inspires awe. That arm-span, that extraordinary ability to flush out lactic acid, that hard work, that informed instinct that gave him the extra stroke to take his seventh gold (100m butterfly) by 0.01 of a second. (And those 12,000 calories he must consume each day.)

Can anybody compare with his eight golds and the way he won them, from history or the present?

Usain Bolt, for instance. Purists argue that his three golds, all in record-breaking times — in the 100m, 200m, 4x100m relay — don’t test enough of the width of ability in athletics that Phelps’s eight did in swimming.

But you had to be at the Bird’s Nest last Saturday night. You had to be sitting at ground level at the finish line, as we were lucky enough to have done, to feel the way he stretched time in that 100m stretch. You had to have felt first-hand the way in which he then connected with every spectator, to know he had made each one of them suddenly aware of the potential of self-improvement of the human race.

And given the disgrace that’s come to 100m with a recent history of doping, Bolt’s run intrigued. It had the potential to either redeem or destroy sprints for the foreseeable future.

So, aren’t those records special?

Then to India. India has never before known how it feels to own an individual gold. It’s been a stranger to multi-sport victory. Now, it has three, a gold and two bronzes. Three does not weigh too much in the great haul of nations. But against a history of nothingness and accidental victories, does three not signal a reversal? How much weight accrues from that?

Really, who ever said a gold is a gold is a gold?