Michael Schumacher brought the curtain down on his 15-year Formula One career at the Brazilian Grand Prix on Sunday and debate will linger for a long time on whether he is the greatest Formula One driver of all time.
The enigmatic Schumacher keeps his private life in the shadows
But his retirement could provide an answer to an even more intriguing question - who is Michael Schumacher?
Schumacher has fought as fiercely for his privacy as he has for F1's accolades.
So in many ways the German's public image has become characterised by his driving - ruthless, cold and arrogant, a machine built to master machines.
But there is another side to Schumacher that remains largely hidden from general view.
"You can only describe Michael in two ways and you have to separate him from the racing driver," says his spokeswoman and ghost-writer Sabine Kehm.
"If he is racing then he is 100% racing, and in private he is 100% private. It is clearly divided."
Schumacher the racing driver, who graduated from driving a homemade kart at the age of four to re-write the F1 record book, is relatively easy to pin down.
Away from the track Michael is a laid back, relaxed guy - he is much less of a perfectionist
He is tenaciously fast and has achieved unprecedented levels of success, while his highly-competitive streak has often spilled over into incidents which many feel saw him step beyond the boundaries of acceptability.
But the man who was willing to move over on Mika Hakkinen at 200mph at Spa in 2000 is the same individual who donated £5m to the Asian tsunami relief fund, the biggest single donation by anyone.
The two sides appear to contradict each other - but that is not the case, according to Kehm.
As someone who has worked for Schumacher for six years, and who was a well-respected German newspaper journalist before that, Kehm knows him better than most outside his immediate family.
She says the two sides of the man are more easily reconciled than at first it might appear.
"Michael has the reputation of being a ruthless driver," she says, "and, yes, he would never give up or avoid a fight on the track. But he can accept defeat if he is happy with the fight.
"Those black spots - let's say 10 situations where Michael was driving really hard - I don't want to make them unimportant and it is justified to criticise them.
Corinna and Michael are a tight unit after 11 years of marriage
"For most of his career, Michael was in a world championship fight and there is so much pressure that maybe at times you overdo it.
"He has won so much that it seems easier to remember the few negative things than the many positives - and that is not really fair.
"Away from the track Michael is a laid back, relaxed guy. He is much less of a perfectionist, he is patient. He is devoted to his family and is a sensitive man.
"I don't think that means he is a paradox. On the track he is an absolute fighter but that is more or less gone as soon as he gets out of the car."
Schumacher has always been cautious about forging friendships in F1 - to the point that even his relationship with his brother Ralf, a fellow driver, has become distant.
His former rival Damon Hill says: "Michael was - and is - always incredibly cagey about himself. He's got a wall around him."
And when Eddie Irvine was asked a few years ago what his then-Ferrari team-mate was like, he said: "Michael likes his dogs, his family and driving racing cars. And that's it."
Schumacher is indeed a man of very simple tastes, even if his interests go a little further than the Northern Irishman suggests.
Kehm reveals Schumacher is "very close to a couple of Ferrari guys" and often spends time playing backgammon with team chief Jean Todt. His two closest friends are family men who he has known since childhood.
Schumacher takes his charity football matches very seriously
He has five dogs at his Swiss home, including a stray he found wandering the paddock at the Brazilian Grand Prix several years ago. He also enjoys skiing at his second home in Norway and plays football for Swiss third division side FC Echichens.
But the single most important thing to him is his family - wife Corinna and children Gina-Maria and Mick.
His serious approach to family life and his involvement in charities is partly inspired by his humble upbringing in Hurth Hermulheim, a small town in Germany's industrial heartland near Cologne.
"Michael's family really had more or less nothing and his whole childhood was comprised of this," Kehm said.
"He and Corinna try not to spoil their kids. He picks them up from school when he can. He wants them to grow up in the normal way.
"He is aware he is leading a very privileged life and is moved by an inner responsibility."
Schumacher's desire for equilibrium in his private life, his quest to keep his family apart, is so strong that he has never been comfortable in the public eye.
But will that become any easier now he is retiring?
He thinks he is retiring and can get out of the public view as fast as possible - I think that is unrealistic
On the one hand, he and Ferrari have said he will take on an as-yet-unspecified ambassadorial role for the team at some point next year.
On the other, he says he will not miss the pressures that F1 has put on him for the last 15 years, and is looking forward to some time to truly relax.
"Michael is very curious about what is happening to him," Kehm said. "He will miss the intensity but really wants to let go for a while."
He has a vision of how he would like his career to be viewed.
"Michael is proud of what he has achieved," Kehm says, "but it is more important to him to be remembered as a pure racer with a great passion for the sport."
But it seems retirement is not going to dim Schumacher's desire for privacy, or persuade him to become more relaxed about exposing his off-track personality.
"He thinks he is retiring and can get out of the public view as fast as possible," Kehm says. "I think that is unrealistic."
It seems even when his career is over the gulf between the public and private sides of Michael Schumacher will remain.