Six-time MotoGP champion Valentino Rossi says he could have been a good Formula One driver had he moved to four wheels when he first drove a grand prix car.
The Italian tested for Ferrari in 2005 and showed good promise, lapping relatively close to seven-time champion Michael Schumacher's laptimes.
Rossi returned to Formula One action on Thursday for the first of two days of testing at the Mugello circuit, where he was roared by around 1,000 fans watching from the stands.
The MotoGP world champion reckons he could have been good enough to be in F1 had he made the switch.
"I have nothing to prove, neither to myself nor to others," Rossi told reporters after the test.
"I only had a big curiosity to know. Well, I'm more and more convinced that with a bit of time I could have become a good F1 driver. It only remains to be seen how good, whether good enough to win or not.
"So I have no regrets, never had them: I did the right thing with staying in MotoGP, where I win and I hope to carry on winning for a long time."
He added: "I want to thank Luca di Montezemolo and Stefano Domenicali for giving me this huge present. This is a celebration for me and for Ferrari, I longed for it, and I'm very happy to be just halfway through it, as I still have another day.
"Compared to 2005 I've found a stronger car, more drivable, with formidable aerodynamics. It's clear that I've tried to go as fast as possible: when you drive a Ferrari you can only go quick, otherwise you stay home."
Rossi covered a total of 320 km during the first day of the test, setting a fastest time of 1:22.550.
Former world champion Kimi Raikkonen's best lap back in September was a1:21.070.
"It's really nice to be here, celebrating a great season with numerous victories, here at home," said Ferrari team boss Stefano Domenicali. "Mugello is one of our tracks and also a circuit where Valentino has won several times, winning in some extraordinary races.
"It's two days of pure fun for us and Vale, although we're doing serious work; you can see that he prepared himself physically. Vale would have been an excellent Formula One driver, but he chose a different road.
"He's part of our family and that's why we wanted to give him this opportunity; we're happy to be together once again; two Italian symbols like Ferrari and Valentino Rossi."