That is the view of his former Mercedes boss Toto Wolff, who admitted to Le Journal de Montreal newspaper that he was shocked when the German announced his retirement shortly after winning the 2016 championship.
But “I knew his idea as soon as he told me,” the Austrian said.
“Nico was no longer willing to make the sacrifices and live through another intense duel with the best driver in the world. He chose to devote himself to his family instead.
“You can’t blame him for that approach,” Wolff added.
Fellow Mercedes chief Niki Lauda agreed: “Of course it surprised me.
“Nico told us later that he would have continued if he had not won his title. He could have told us that before.
“But I think Valtteri has proved to be a worthy substitute,” Lauda added.
Lauda has played down the likelihood that Rosberg will ever return to F1, but Wolff does not agree.
“I’ll let you know something,” he said. “I would not be surprised to one day see Nico racing at Ferrari or someone else.
“He’s only 31, he’s still young. Perhaps he will change his mind. I don’t know.”
But Wolff said he doubts Rosberg will try to emulate Fernando Alonso’s recent bid at Indy 500 victory.
“Knowing him, Nico will not try his luck there. It’s a dangerous adventure,” he said.