In years to come, those fortunate enough to have been inside Newlands on the second day of this match will regale strangers in bars with tales of the time Ben Stokes bullied the No. 1 team in their own backyard with a performance that stands comparison with any of the great innings in England's modern Test history.
They may struggle to summon the words to do justice to the brutality they witnessed; the acceleration of the innings; the power of the boundaries. And, even if they do, those listening will think they are exaggerating.
Because this was an extraordinary, magnificent innings. It made a mockery of the usual pace of Test cricket and the usual practice of easing into a morning. It made a mockery of South Africa's attack and many Test records. It was magical.
Chris Broad, during his brief spell in the media, once remarked that he had "run out of expletives" to describe a passage of play. While you suspect the word he was searching for was "superlatives", it felt like an apt description for the butchery Stokes inflicted here. Had he worn a cape, he could not have appeared more like a superhero.
This innings has been coming for a while. To see Stokes bat in the nets, or in the warm-up matches at the start of this tour, was to see a beast straining at its leash. Net bowlers were devoured and, in one case, forced to hospital by the brutality of his hitting. The timing, the power, the hunger were all evident. Sooner or later, an attack was going to suffer. This one won't be the last or the best.
We have seen glimpses of his abundant talent before. In just his second Test, he made a deeply impressive century at Perth against Mitchell Johnson, Ryan Harris et al, as his teammates fell around him. Then, in May 2015, he scored the quickest Test century ever made at Lord's as he led England from a precarious position to a match-winning one against New Zealand. He appears to relish pressure and responsibility.
There was a deluge of records here; a statisticians' dream. Had Stokes' innings lasted as long as Alastair Cook's innings of 263 in Abu Dhabi, he would have scored nearly a thousand. Yes, it is ridiculous statistic. It was a ridiculous day.
But statistics cannot convey the magnificence of this innings any more than they can convey the magnificence of the mountain that overlooks this ground. So, just as reading that Table Mountain is 1,084 metres tall and made of Ordovician rock and quartzitic sandstone cannot provide any sense of its verdant slopes, its ragged edges, its irresistible beauty, so knowing that Stokes hit more sixes than any Englishman in a Test innings and made the second fastest double-century in Test history does not provide any sense of his dominance over the South African attack.
But there were a few moments towards the end of the innings when the look on the faces of the South African fielders betrayed the enormity of what was unfolding. They were looks we see very occasionally at this level: the look on Mike Gatting's face when Shane Warne delivered that ball; the look on Graham Gooch's face when Ian Botham returned from a drugs ban and, within two overs, had claimed the two wickets he required to become the highest wicket-taker in Test history; the look on the faces of the Australian attack after Brian Lara had led West Indies to a one-wicket victory in Barbados with an unbeaten 153. The look on the faces of many bowlers who tried to contain Viv or Sachin. It was a look of awe.
Typically, in this innings, it came when a fielder positioned on the boundary saw the ball coming their way. But just as they steadied themselves for the catch, they realised the ball wasn't slowing down or dropping. It was, at times, still rising. It was going yards over their heads. Balls landed beyond grass banks and stands as Stokes produced a passable impression of an overly competitive father thrashing his toddler child's bowling around on the beach. Just for a while, the South African bowlers knew exactly how that locker in the Barbados dressing room felt. Maybe a few batsmen have hit the ball harder; not many spring to mind.
Not that Stokes is a mere bludgeoner. He times the ball with a sweetness granted to few and he has a wide range of strokes. It's just he also hits it hard. So to see the sweeper on the cover boundary hardly move before another ball rushed past him, or to see the mid-off stand motionless as another ball sailed over his head was to see artistry and brutality combined. It was to see precision bombing.
Jonny Bairstow lent mature, polished support with an emotional century that deserved headline billing of its own. Not attempting to compete, he showed impressive acceleration of his own once the orders to do so were given and underlined the impression that he is every inch a Test batsman in both temperament and technique. On this day, however, he was destined to be the support act.
South Africa started the day by bowling full at Stokes in an attempt to draw him into the drive. Up to a point it worked, too. He certainly was drawn into a few. It was just that every drive he attempted flew to the boundary with a sense of dominance that soon persuaded them that the plan wasn't going to work.
So then they went short at him. And, against a man so comfortable with the short ball and as strong on the pull, that is where things grew ugly for them. So well did he time the ball that only 22 of his runs came behind square on the leg side. So well was he seeing the ball, so well was hitting the ball, that nearly every pull, hook and clip went in front of square. He loves pace and, on a pitch as true as this, was able to hit through the ball with an ease which rendered no length safe.
The third stage of their attack was shell-shock. They didn't know where to bowl and it didn't seem to make any difference. They tried full, they tried short, they tried length. All to the same end. He was flowing now. He was unstoppable.
Do we need to compare this with other great England innings? It was neither better nor worse than Gooch's 154 against West Indies in 1991; just different. It was neither better nor worse than Kevin Pietersen's trio of 2012 centuries; just different. We don't always need to categorise or choose. Sometimes we can just admire and enjoy. And let us not forget, when he came in, Kagiso Rabada was on a hat-trick and England were in grave danger of squandering first use of this pitch. It would be a miscarriage of justice if this innings is remembered as soft.
Do we have to crush every joy with caveats and context? Oh, okay. This pitch has been, up to now at least, the sort of surface a batsman wants to whisk away to Paris for a weekend of tender lovemaking, while the bowling attack - missing Dale Steyn and Vernon Philander - was largely green and increasingly ragged. In the first session of the day, there was scarcely a slower ball delivered and, whatever plans there might have been, were soon abandoned to chaos. Hashim Amla has many qualities; captaincy may not be one of them.
But it is hard to keep your head in a tornado and it seems churlish to diminish this innings with such observations. It would be like telling van Gogh the painting of his bedroom was wonky or asking Bob Dylan to sing properly. Genius has its own rules and this was genius in action. Besides, as Stokes thrashed perfectly respectable length-balls from Morne Morkel back over his head, you had the impression that it did not matter what South Africa did now and that Steyn, for all his heart and skill, might reflect that this wasn't such a bad surface to sit out. Had a lion wandered on to the playing area, Stokes would simply have wrestled it into submission. This was his day.
It may be his era. Young men don't come with guarantees and there will be days, no doubt, when the shots find hands not stands. When it is suggested that Stokes is reckless. When he is said to have "given it away". He has some issues against spin, too, which will have to be conquered before he is considered one of the world's most promising young batsmen and rarely looks quite as comfortable upon the sluggish surfaces on which he may have to play most of his career.
But there is no reason Stokes cannot shape many more games. He is, aged 24, the youngest man in the England team. He is still learning, still improving, still hungry. He mentioned afterwards that, knowing the likes of Bairstow, Moeen Ali and Stuart Broad bat after him has given him the freedom to attack without inhibition and that he gives no thought to averages.
Quite right, too. For Stokes is a far from average cricketer. And if we were foolish enough to judge him in those terms, we would conclude he was a pretty modest talent. He did, after all, come into this innings with a Test batting average of just 27.72.
Stokes should never be tamed or changed. He is not a percentage cricketer; he is special and he can damage opposition within a session. England have found a gem in Stokes and this may well be his time.
George Dobell is a senior correspondent at ESPNcricinfo