Having spent time with Alonso on Wednesday, in the hours after his bombshell announcement, you quickly came to realise that here is a man more determined than ever to get himself back to the front of the grand prix grid.

After all, it would have been all to easy for the Spaniard, on the back of a disastrous pre-season testing programme, to have thrown his towel in on the McLaren-Honda dream and walk away to go spend more time cycling and sitting on a beach.

But Alonso has not earned his reputation as one of F1's toughest fighters for nothing, and it was ultimately no surprise to see him astonish his team and many observers worldwide with some brilliant performance in the uncompetitive McLaren in the opening two races of the season.

Yes, his claims that Australia and China were the best races of his life may be more of a plot to make the world be sure he is driving better than ever – as a 'come get me' sign for 2018 – but it is fair to say he is still a man pushing hard.

In fact, you get the distinct impression that the below-par start to the year from McLaren has afforded Alonso some time to reflect much deeper on where he is at in his career, to decide for himself if it is time to walk away or time to actually push harder, extract more from himself and deliver the kind of commitment that only those fighting for the world title can deliver.

There have been some sideshow boosts along the way too, with his high-ranking battle with Lewis Hamilton for a spot at F1's most popular driver in the Global Fan Survey delivering him a bit of a morale boost, proving that his years away from the podium, of competitive frustrations on track, have not lessened the appreciation of those who follow the sport.

His decision to race at Indy, and in doing so skip the Monaco Grand Prix, is not about giving up on F1 then: it is about taking the next step in becoming a more complete driver, in challenging and pushing himself and finding new limits.

And in doing that, in better understanding himself and what he wants from life and racing, can he find the right path for himself in F1.

Asked at a press conference on Wednesday about whether or not racing in Indy was a sign his commitment to F1 was fading, he was instant in dismissing the idea.

"It is probably the opposite," he said. "It's to show that I want to win everything that I am participating in. In F1 we don't have also the perfect package now to achieve that and, as a team, we are open to participating in more things.

"But my full commitment is still in F1. I want to win the third world championship and hopefully this year we can see some of these signs – of some podiums and race victories which at the moment are a dream for us, because we are so uncompetitive. But the season is long and we are all working to make this happen."

What Alonso's Indy announcement has done too is remind the world about the power of the Spaniard as a superstar.

He alone got #Indy500 trending on Twitter; he alone has the power to increase F1's reach in America for two glorious weeks in May; and he alone has rivals offering their help to make motor racing's biggest potential fairytale come true.

Within seconds of the announcement, for example, Alonso's mobile phone received a short SMS from former Indy winner and actual 2017 competitive Juan Pablo Montoya.

It read: "Felicidades por la Indy 500. A sus ordenes!" Translated - "Congratulations on the Indy 500. At your disposal."

However Alonso's Indy 500 performance goes, he will return to F1 at the Canadian Grand Prix with a much clearer indication of where he wants the next step of his career to go.

From then on, much will depend on the rate of progress that Honda can make: if it is delivers enough to give Alonso the sniff of podiums and wins that he so craves, then summer talks with McLaren could yet result in a fresh contract.

But if progress on track is slow, then it will not have gone amiss in the corridors of Enstone, Brackley and Maranello that F1 has a fired up superstar, still delivering at his very best, with a hunger to achieve much more in F1.

"I expect a huge improvement from the McLaren-Honda F1 team and to be able to fight for podiums and victories at one point in this championship," explained Alonso this week. "That is everything in my head.

"I consider this Indy 500 an amazing opportunity to race in this spectacular race and a step closer to this triple crown that I want to achieve one day. But for the future it doesn't mean I will be closer to the [McLaren] team because of this. It is a one off because it is a special event.

"I don't consider my future will be in the USA, all my driving skills and technique are developed for F1 cars and this is what I want to do in the future."

Alonso and F1 are not done yet.