It was the fastest dance in history. Bolt spread his arms, slapped his chest, lifted his knees to his chin and danced 100 metres in a reality-defying 9.69 seconds.

The final of the men’s 100 metres at the Olympic Games is the greatest occasion in sport — the race of races at the event of events. To be in the Olympic Stadium when a world record is broken is like nothing else in sport. I remember — cannot forget — the desperate brilliance of Ben Johnson’s run in Seoul 20 years earlier. A world record was followed with devastating speed by the devastation of disgrace.

As the rounds ticked down in the 100 metres at the Beijing Games of 2008, so Bolt ran faster and faster. He loped into the final; only the clock thought he sprinted. The 100 metres final is supposed to be gunfight-crazy, hair-trigger nerves, macho posturing. Bolt strolled to the line like a man at a mildly amusing party.

Bang. Bolt got to his feet, always a protracted business. Found his stride, again, not a thing he does in a hurry. And was gone. Clean gone. He danced his dance in the final few strides and still set a world record.