Reaction to Nico Rosberg's shock retirement has been surprisingly polarised, between anger and understanding.
On the anti side are those who believe a champion owes it to his sport to defend his title. Who want to see him try and beat Lewis Hamilton without the mechanical mayhem that compromised the Englishman's title campaign but not his own.
Others get it completely. You only have to listen to Rosberg speak of his daughter Alaia, and to watch the way he and his wife Vivian celebrated his triumph in Abu Dhabi, to see where his roots really lie. After 25 years of chasing the dream, a family man is ready to step back, the mountain scaled. Achieving his life's ambition was super-tough, especially against a warrior such as Hamilton, but he made it and he can leave the sport with his head held high. Just like Jackie Stewart did in 1973, his third crown won, or Alain Prost 20 years later, his fourth title secured.
There's no rule that says you have to hang around, and perhaps "enjoy" the sort of embarrassing title defence that bedevilled Jody Scheckter in 1980, when he scored but two points. Knowing when to quit is all part of the game, and Rosberg knew his mind better than anyone else did.
This was no spur-of-the-moment thing, and he is unlikely to regret it in the years to come. Only he knows what it took out of him to lose two years running to a team-mate universally acknowledged to be a faster and more complete racer, let alone to come back time and again until he succeeded in beating him.
Knowing when to quit is all part of the game, and Rosberg knew his mind better than anyone else did
Team boss Toto Wolff called it a brave decision, "which proves Nico's strength of character".
"This season, I tell you, it was so damn tough," said Rosberg.
"I pushed like crazy in every area after the disappointments of the last two years; they fuelled my motivation to levels I had never experienced before...
"When I won the race in Suzuka, from the moment when the destiny of the title was in my own hands, the big pressure started and I began to think about ending my racing career if I became world champion... I took my decision on Monday evening. After reflecting for a day, the first people I told were Vivian and Georg (Nolte, from his management team), followed by Toto."
He admitted that his only problem was leaving his team in the lurch, and of course the focus now turns to what effect his retirement will have on Mercedes.
The answer is that Mercedes lose a doughty fighter, the man who just wouldn't go away. For Hamilton, it could mean having a slightly easier time of it in 2017 - not that he would welcome that - but much will depend upon whom Mercedes hire to drive alongside him.
Might we yet see another surprise, were Fernando Alonso, for example, able to extract himself from McLaren? Might the offer of a one-year deal for the "retired" Jenson Button, a former Hamilton team-mate, provide the answer?
Is this the magic carpet that will take Pascal Wehrlein from a back-of-the-grid Manor berth to a race-winning seat?
The reverberations from this bombshell have not subsided yet..