I'd been reading about father & son Rosberg, and about the fact that Keke won his championship, with only winning one race. I've watched F1 since the late 70's, but couldn't remember Keke winning in 1982.
It transpires it wasn't one of the best years. Started off with a drivers strike. Gillies Villeneuve was killed during the closing stages of qualification for the Belgian GP, after striking another car, his went airborne and he was thrown from the car, cartwheeling into the catchment fence. Italian Riccardo Paletti crashed into a stalled car off the grid at the Canadian GP. As they later tried to extract him from the wreckage, the vehicle caught fire, taking some time to put out the flames. He later died. There are of course, disturbing videos of these incidents.
After surviving a serious crash at the French GP,
Jochen Mass was a lucky man to hobble away with minor burns, but such had been the impact of Villeneuve's death on the German, that he took his own accident as a sign that he needed to quit the sport. He would never race again in a F1 GP. Towards the end of the season, it was looking as if Didier Prion would win the championship, but a massive crash in the German GP, meant he never raced again.
So Keke Rosberg went onto win the 1982 F1 Championship. If Villeneuve had lived, he may have won that year, then it would have been his son, Jacques, who would have been the second father son champions in 1997.
I think we do forget how dangerous motor sport is, but with vast improvements made on safety & construction of the cars in the last few years, fatalities are not so common. We only have to look at Alonso crash in Australia this year to see that, where he walked a way with just a few bruises.
So perhaps I do understand why Nico Rosberg has decided to call it a day. Been there, done that, got the tee shirt.