Greatness reveals itself in many ways and not just in its moment of ultimate triumph. That Michael Phelps' victory on Tuesday morning in the 200m freestyle final - his third gold medal performance of the 2008 Olympic Games - was a breathtaking display of athleticism is beyond question, but in his quest to make history it isn't just what he does that counts but what he does next.
Clearly, next cannot come quickly enough for the 23-year-old American, who now stands five gold medals short of immortality. The gawping jaws of the watching world had barely been reset after his crushing, world record-setting victory in the 200m freestyle when Phelps was back on the blocks, this time for the semi-final of the men's 200m butterfly.
He won that, too, but in a fashion that spoke not of a man in hurry but of a man on a holiday; a short but languid break from the stress of being the most talked-about athlete in the world.
While others splashed, he glided. While opponents were relieved to advance to the final, he set an Olympic record of 1:53.70. Caribbean cruises have never looked this relaxed. He will try to win his fourth gold in this, his specialist event, just after breakfast in Beijing Wednesday morning. He will then follow that by swimming his leg for the United States in the 4x200m relay final.
There can be few people around the world, and even fewer around the world of world-class swimming, who believe he will be denied two more triumphs when Wednesday dawns, although there was one doubting voice seeking to make itself heard above the clamour. That of Phelps himself.
“I am not even halfway done yet,” he said when the inevitable questions were asked of his quest for a record eight gold medals; about whom or what he considered to be his biggest remain obstacle. “Most of the important races are to come. In every event people are swimming faster. Everyone is my rival. Tomorrow is a big morning with the 200m 'fly and the relay. I am very happy with things so far but I will take one race at time.”
In the circumstances, it was even possible to forgive Phelps' evocation of the hoariest old cliché in the athlete's lexicon. If it works for him, so it should work for us. He is not a poet, after all, but a swimmer on the cusp of becoming the greatest Olympic swimmer of all - an unofficial title held for more than three decades by his countryman Mark Spitz.
This morning's victory in the 200m freestyle final earned him the ninth gold medal of his Olympic career, tying him with Spitz and the sprinter
Carl Lewis. Less notably, although perhaps not for Phelps himself, it also served to compensate for his third-place finish in the event at Athens in 2004; a defeat that ended his quest for eight gold medals, and also made its mark on his psyche.
“Four years ago I hated to lose that race,” he said, in a fleeting confession of human frailty. “And when I lose like that it motivates me to swim faster and over the last four years I have been able to drop [lose] some significant time in the 200 freestyle.”
Significant is one way of describing the time he dropped en route to Tuesday's triumph, unfathomable is another.
As for Lewis and Spitz, the twin giants of Olympics past who stand ready to be toppled from their pedestal, Phelps was no less respectful.
“It is a pretty amazing accomplishment to be tied alongside such great names from Olympic history,” he said. “I have spent time with Lewis and exchanged words with Spitz. It is a tremendous honour to be with them.”
Frankly, Mr Phelps, the honour is all theirs. And ours.