Even now, at 25, he would struggle to buy anything stronger than a ginger beer without being asked to produce ID – when he was told he couldn't drink podium champagne in Turkey last year, because the new alcohol limit was 24 and he was only 23, it seemed strangely appropriate. But his youthfulness makes his precocity all the more astonishing. Vettel could win his fourth race in a row in Delhi and if he does he will look certain to become only the third driver to land a hat-trick of titles, following Juan Manuel Fangio and Michael Schumacher.
That may not be enough for Sir Jackie Stewart, who said recently: "To really show you're one of the greatest, you have to deliver when you haven't got the best machinery. I have the highest respect for Sebastian, but he could not have achieved what he has without the [Red Bull design chief] Adrian Newey factor. If you've got a superior car, it's relatively easy to win the championship."
There are others who feel that Vettel has achieved what he has on the back of Newey's genius – but that is only partly true. The seriously fast Mark Webber drives the same car, and he languishes 63 points behind his team-mate. Besides, Red Bull have not had the best car all season.
Vettel's outstanding ability is enough to convince most judges. And most particularly it is enough for Bernie Ecclestone, the sport's 81-year-old chief executive, who believes that the German will go on to become the greatest driver of all.
Ecclestone, taking time out from responding to reports that he is about to be sued by one of Germany's leading banks for £250m and may even be in danger of losing his grip on the sport, told the Guardian: "I see no reason why Seb can't go on to achieve what Michael Schumacher has achieved in this sport, which is unsurpassed. And Seb is up against much tougher opposition than Michael was. He's very honest. He's very dedicated. And he's very talented. He has made sure that he's exploited his capabilities to the maximum.
"We've always got on well. And I think it helped us get on when he came into the sport and I identified him, straight away, as someone who would be world champion. We get on, we chat together, joke together and play backgammon together. I have always looked for people I can beat at backgammon."
Ecclestone and Vettel are the odd couple of Formula One, friends despite an age gap of almost 57 years. On Thursday evening Vettel and his girlfriend, Hanna, dined with Ecclestone and Red Bull's team principal, Christian Horner.
Horner said yesterday: "They share the same cheeky sense of humour. Sebastian has a tremendous grasp of British humour and he likes trying out his cockney slang on Bernie.
"It is unusual that two people with this age gap become good friends but Sebastian has a very mature head on his shoulders for a 25-year-old and Bernie's got a tremendous active mind that belies his years.
"Seb rarely wins the backgammon and if there is money involved definitely not. Sebastian has a great interest in the sport as well, and Bernie has seen so much, been involved with so much, I think Seb enjoys talking with him about the old days."
Ecclestone has rarely been as close as this to one of his drivers, though he was friendly with another German-born world champion, the Austrian Jochen Rindt, who became the only driver to win the Formula One title posthumously, in 1970.
But Ecclestone is not the only one who believes Vettel will become one of the all-time greats. He has already won more poles (34) than any other driver apart from Schumacher and Ayrton Senna and triumph this year would see him join the five men who have won the championship three times – Senna, Nelson Piquet, Niki Lauda, Jack Brabham and Stewart.
It is the serenity and swiftness of his progress which have impressed. Last year he eschewed the mistakes he made in his maiden championship season of 2010 to dominate the campaign. "I don't make the same mistakes twice," he said here on Thursday, which must have sounded rather chilling to his pursuers.
Schumacher, who has won the title a record seven times, said this week: "In the long term, I think Sebastian will go on to become Germany's Mr Formula One."
Vettel, who was fastest in practice, goes into the Indian Grand Prix with a six-point lead over Fernando Alonso, with four races to go. But the force is now with Red Bull. They have made a number of upgrades in recent races – most importantly the new front wing that arrived in Singapore – and more are expected here.
And that is why Vettel is about to upgrade himself from a double to a treble champion next month.
guardian.co.uk © Guardian News and Media Limited 2010
image: © PresidenBertho