Throughout history, the question of when to stop and when to carry on has always plagued top drivers. Vanishingly few go out on their own terms, as Nico Rosberg did in a shock retirement announcement just five days after winning the 2016 world championship.

At the time, he admitted that the challenge of beating Hamilton over a season had left him empty. His objective was to win the title, he scaled that mountain and had no desire to put himself through the cold, the physical discomfort and the altitude sickness again. He was either happy with what he achieved, or recognized he probably wouldn’t be able to win the title again and accepted it.

“This year was extremely tough because I put everything into it, I didn’t leave a stone unturned and pushed like crazy in all directions, along with everyone who was involved,” said Rosberg at the time. “This was also my family, [making] a lot of sacrifices. My wife, for example, every time I was home she understood that I needed to rest, so I never did any nights, I never took care of my little daughter, I never did any difficult things. She was always there to support and to make it as easy as possible, and that is just one example of the commitment we all put into it.

“That’s why I’m not willing to make that sort of commitment again for another year. And I’m not interested in coming fourth. I’m a fighter and I want to win. But I’m not interested to do that again. I don’t want to do it again. So I’ve decided to follow my heart, and my heart has told me to stop there, call it a day and go on to other things.”

But as Alonso and Vettel show, such an attitude is rare. Michael Schumacher couldn’t leave F1 alone and came back after three years out with Mercedes with a clear objective – to win the world championship. He retired a second time after three seasons that yielded a solitary podium and one qualifying-topping performance at Monaco in 2012 that was for nothing because he had a grid penalty for wiping out Bruno Senna’s Williams in the preceding Spanish Grand Prix.

Schumacher came out of his first retirement with a more outwardly relaxed approach than during his prime, even though he was unable to recapture the Ferrari magic at Mercedes. Image by Motorsport Images

During his three years, Schumacher did appear to come to terms with his lot and accept that the title wouldn’t return and seemingly enjoyed himself. He was certainly a more relaxed figure, so perhaps he found a little of what Raikkonen has done. Certainly, when I asked him at Interlagos nine years ago about suggestions from some quarters that he returned because he couldn’t fill the hole left by quitting F1 at the end of 2006 left in his life, he railed against it.

“I had a great career and for three years I had lots of fun. The biggest thing was that I had the freedom to live the way I wanted to live, something that I missed out on in all the years before,” said Schumacher in 2011.

“So why did I come back again if I enjoyed it so much? The main part is that I was doing competition anyway, but after my motorcycle accident it sort of cleaned up my ambitions there! Secondly, I was doing go-karts and enjoying it.

“My intention was simply to come back and enjoy the sport – the challenge, the competition – due to the fact that there was this combination of Ross [Brawn] and Mercedes that I didn’t even dream about. It just came out and I took the decision of why not again? If you had asked this two years before, I certainly would have said no.

“I wouldn’t have the energy any more to do testing and racing as I used to do, but what we have now is very easy for me. The timescale works out.”

Even Jenson Button had something of the same problem, flirting with retirement before eventually dropping off the grid after 2016. While he was content to have won the title, what he was driven by was race wins, and the desire to add to his tally of 15 led to him hanging on in the hope the McLaren-Honda project would break through.

Others, like Mika Hakkinen, had no choice but to quit when it became clear they didn’t have much fuel left in the tank. The Finn won two world championships, lost out on a third to Michael Schumacher but firmly lost his mojo in 2001 – only occasionally delivering his best form and opting for a sabbatical that became retirement. Even Hakkinen briefly flirted with the idea of a comeback before being disabused of the notion by his struggles in a test for McLaren in November 2006, having run competitively in DTM.

The other leading drivers from that era – Damon Hill and Jacques Villeneuve – also both struggled. Villeneuve battled on in F1 until being dropped by BMW Sauber during 2006 and continued to seek ways back onto the grid, and is still active as a driver today. Hill realized in 1999 that he’d run out of steam, but was obliged to see out the season after having decided to stop in the middle of that year.

In fact, the number of world champions who have been able to stop on their own terms or accept a slide down the grid is vanishingly small. In the previous generation, Alain Prost toyed with continuing his career with McLaren in 1994 having retired as world champion, while Nigel Mansell’s determination led to his debacle with the same team the following year.

But what is rare is for any of them to be able to continue in their chosen sport for fun, Raikkonen-style. He can be frustrating because he is a prodigious talent who perhaps hasn’t had as much success as he might have done, so is perhaps a little too relaxed with life. But he’s probably a more content human being for that.

You could argue Alonso and Vettel should learn from that, but they are probably not wired that way. If they were, it’s hard to imagine them having achieved so much.