"Some of the best generals have been young men. Alexander the Great was just 21 when he had conquered half of Europe," he said. "So it is a mindset. Some guys are very strong individuals and know exactly what they want out of life."
De Jager is a case in point. All puppy face and gentle giant off the field, he becomes a monster on it, his 50 tackles in four pool games the most by any player at the World Cup, and the chief reason he was always going to be picked ahead of 38-year-old Victor Matfield, who would have played off the bench had he not re-injured his hamstring in training on Tuesday.
Damian de Allende is another for whom age is nothing but a number. The second five-eighths has taken to test rugby quickly and his match-up with the thunderous Jamie Roberts will be one of the game's fascinating sideshows. Neither knows how to take a backward step.
In any case, the younger players are surrounded by seasoned pros. Injury has removed the two oldest players in the squad in Jean de Villiers and Matfield and there is now a better blend of youth and experience.
Meyer has a point when he says this team is only going to get better, but will they get the opportunity to do that in this World Cup?
"It has not been easy to come to the World Cup expecting to hit the ground running only to find ourselves in reverse ... but having to switch to 'knock-out mentality' from the second game has helped steel us for what lies ahead tomorrow. Nothing has changed for us since Samoa became a 'must-win' in round two. It suits us, having our backs against the wall and knowing exactly what we have to do - win every single game to become world champions. I think it helped us. You also have to respect your opponent as well. They have also been under huge pressure in their pool and earned the respect of the rugby world for their performances against England and Australia."
Meyer's parting shot sums up this game. "A correctly focused, hungry Springbok team that is playing to its strengths should win nearly every game they play. We won't have a problem with any of those requirements, that's for sure."
Wales out for new era against Boks
As much as Sam Warburton dismisses its relevance, the history between Wales and South Africa is too lopsided to ignore.
Two wins over the Springboks in 109 years is not a rivalry.
The second win was just last November; 12-6, all penalties, in Cardiff. Can Wales take much from that into their Rugby World Cup quarter-final with South Africa tomorrow?
A little. First, it has prevented the buildup this week from becoming an inquisition on Wales' miserable streak against the Springboks, All Blacks and Wallabies.
Until that win in Cardiff, Wales had lost 22 straight to the big three, choked in too many of them, and coach Warren Gatland was starting to get cranky. Alas, a new streak, of one, has begun following Wales' inability to score in the second half against an Australian side down to 13 men in pool play last weekend.
The second benefit was that 10 of those Wales starters, especially seven of the forwards, have survived to line up in the quarter-final and know what it takes to beat South Africa. They made the mental jump, although the physical one is unforgettable, too. Warburton admits the body was in a pretty bad state after playing the Springboks.
The doubt about Wales' ability to repeat is that South Africa's team is barely recognisable from November. Only five starters have survived from that lineup - these Springboks are bigger, faster and younger.
But there are doubts about them, too. Their record is 4-4 this season, their worst since 2011, the last Rugby World Cup year. They haven't beaten anyone ranked in the top six for nearly a year. The nadir was Japan, a humiliation which also galvanised them. They rebounded to win their pool by dismissing Samoa, Scotland and the United States, effectively padding their try-scoring statistics.
This week, the Springboks have only had to worry about which players to leave out, unlike the battered Welsh, who have worried about who to bring in. In the end, both made minimal changes.
South Africa coach Heyneke Meyer was able to extend the promotion of youth, including prop Frans Malherbe, lock Lood de Jager, first five-eighth Handre Pollard, and centre Jesse Kriel. Meyer made an impassioned plea of support for his younger players by trying to inspire them with similar youthful triumphs by Boris Becker, Mike Tyson, and Alexander the Great.
If those three had anything in common, it was fearless ambition to rule the world.
To that end, Wales and South Africa present major hurdles for each other.
Wales have done remarkably well despite a crippling amount of injuries, while South Africa has regained some swagger but without appearing convincing or being truly tested. It makes for another even-looking contest between two settled teams with formidable packs.
South Africa's backline has an advantage of longevity, but Wales' bits-and-bobs backline and under-rated defence have conceded only two tries, and few penalties.
Both teams are preparing to grind each other down and force penalties.
"When you get to this level, there are not too many weaknesses in teams, so it is not really about trying to exploit a weakness in South Africa, because I don't really think they have any," Warburton said. "It's more just trying to stop what they are pretty good at. It's a big job up front, so we have to be very good there."
South Africa's overwhelming history in this match-up gives it the edge, but a Gatland-coached team can never be counted out.
- Foster Niumata, AP
