Australia hold an unbeatable 2-0 lead in the three-mach series after winning the second Test by 112 runs in Durban on Tuesday.
Langer was 22 when he made his debut in the fourth Test against the West Indies in Adelaide in January, 1993, scoring 20 and 54. But his debut will be remembered for the crunching blow he took on the helmet from a bouncer bowled by Ian Bishop.
''I hardly knew any of the guys I was playing with, and the guys I was playing against I had just seen them on TV,'' Langer told a news conference in Johannesburg.
''I was like a little kid and to face that baptism of fire, I wondered if I would ever recover from that.'' The Perth-born left-hander, who played just eight Tests in the first six years of his international career, earned most of his success after re-inventing himself as an aggressive opening batsman.
Langer, 35, has shared 5,314 runs with Matthew Hayden at the top of the order. West Indians Gordon Greenidge and Desmond Haynes hold the world record with 6,482 runs.
South Africa have added batsman Hashim Amla and fast bowler Dale Steyn to their squad.
Amla, who turns 23 tomorrow, forced his way into the reckoning by scoring 873 runs at an average of 62.35 in 10 Supersport Series matches this season.
Steyn has taken 41 wickets at an average of 17.68 in eight matches this summer.
South African captain Graeme Smith, whose team has lost four and drawn the other of the five Tests they have played against Australia this season, said solid performances from key players had proved to be the difference between the sides.
''I think we're pretty much the same, but when Australia get into trouble they seem to get themselves out of it,'' Smith told a news conference.
''They have experienced players at the top of the order who have done so well, and they've got (leg-spinner) Shane (Warne) who comes into his own as the game goes on.
''(Fast bowler) Brett Lee has bowled superbly throughout the summer, their key performers have done really well.
''(Michael) Hussey has come in at number five, and you can see how his record of having played over a hundred first-class games has benefited him.'' Australia won their home series against South Africa 2-0 in the first half of the season.