This Saturday Mark Cavendish will begin his second Giro d'Italia firmly established and recognised as the most exciting and charismatic young talent to hit cycling in recent memory.

It now seems almost unbelievable that just over two years ago Cavendish's first pro-team coach told him he would never be good enough to be a professional bike rider. The Manxman's roots make his success story even more unlikely: a former bank clerk and amateur ballroom dancer, the chances of him consistently blasting to victory at 70kmh on the roads of Europe seemed slim. But now, his total of 36 victories in three years, around one win out of every seven races he's taken part in, are an unquestionable indication of his talent.

There's no arguing either with four stage wins in the Tour de France last year. Or with taking the Milan-San Remo Classic in March, the Holy Grail of the sprinters races, at his first attempt at 23. Becoming the best road-racer Great Britain has ever produced is something the fans have accepted as a mere milestone in his career.

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Cavendish is on the fast track towards becoming, as fellow racer David Millar says "a true great". But there are often accusations that he is too cocky. Talk to the man himself and Cavendish makes no apologies for pushing the bar upwards so high, so fast. "I've said it before and I know some people think I come across as arrogant but I do achieve what I say I'm going to do," he argues. "There has to be a point and a logic to why you want something. It's about knowing what you want. It's not about being over demanding, it's about having the balls to do what you know is best for you."

Still, there's also a humble streak behind his brash veneer. After winning San Remo, Cavendish refused to buy himself the Audi R8 he had promised himself if he won, because when it came to it, he was afraid it might change him. Rather than move to Monaco or Switzerland as most top riders do when they hit the big time, Cavendish has remained in the Isle of Man. Together with his fiancée, Melissa, he bought a farmhouse near Douglas, just up the road from his mother's place. "Living here is my way of staying close to my roots. Here I know what I am, where I am."

Inside his farmhouse, there is only one trophy on show, from the Belgian Scheldeprijs race, the first he won as a pro. It is as if he wants to remind himself that for all he's now recognised as the fastest rider on two wheels, this is where he comes from.

Cavendish certainly has retained a calculating, almost mathematical, outlook to his sprinting from his bank clerk days. He improves his dash for the line through endless games of speed chess. Couple that with an elephantine memory – he says he is able to recall every single dash for the line he has been in since the Tour of Berlin back in 2005, and is constantly reanalysing them for mistakes, working out the odds.

Cavendish is also a bookworm who devours race manuals. Every evening, while his team-mates are calling their wives and partners, Cavendish will be committing the finer details of the next day's stage to memory.

"I will read it for an hour, maybe more, even if it's the top of a mountain," Cavendish says. "I need to know it down to the last detail." So obsessed is he with knowing the terrain of the finish that he makes the team send out someone to walk the last four kilometres of the big stages, just in case.

He is, he says, not exceptionally talented, but this meticulousness is typical of someone who is exceptionally driven. Fear of failure is what seems to motivates him: "The races where I could have done better where I didn't, that feeling just eats me alive."

After losing a race he expected to win in Belgium last year, he now says "I don't just rely on my strength. Now, I win from the front, and by a heck of a lot more."

"I never demand the impossible. I'm a perfectionist. There's no excuse for failure. I never want to be one of these people who say, I should have done this, I could have done that."

It is to his credit that Cavendish recognises that in comparison to British riders 10 years his senior, he has had an easy start to his career. As recently as the 1990s, turning pro in mainland Europe for British riders was a question of putting a suitcase in the back of the car, getting on the Channel ferry and crossing your fingers you struck gold. That wasn't Cavendish's case. "I was lucky that British Cycling helped me. I would have gone to Belgium to do it the old way and I'm adamant to this day that I would still have become a professional. Maybe I wouldn't be where I am now at 23 and achieved what I've achieved but I would have made it."

Ask him about doping, professional cycling's scourge, and Cavendish points out that he's been tested over 60 times in the last year. He was also the first rider to sign the new anti-doping charter created by the Union Cycliste Internationale back in 2007. His team, Columbia-Highroad, have their own independent anti-doping regime, far stricter than that of the cycling authorities.

Despite keeping his roots back home, Cavendish bases himself in Quarrata in Tuscany during the cycling season, has recently bought an apartment, and has taken to the Italian lifestyle. He confesses freely that he's addicted to Italian designer clothes, adores the local food and just like every male Italian 20-something-year-old, when not riding his bike he potters around town on a Lambretta.

As for the Giro, Italy's biggest race and the second biggest in the world, he has his eye on taking three stages, one more than last year. And like every Italian pro, Cavendish lays special importance on winning his "home stage" – into Florence, the one closest to his base in Quarrata. "On top of that, I really want to get the leader's jersey in either the opening team time-trial or a little late."

Although he will almost certainly have to pull out of the Giro at some point to keep intact his chances of doing well in the Tour – the season's main goal – he is refusing to say when, arguing it's disrespectful. However far he goes, in the dash for the line in the flat stages that are Cavendish's natural hunting ground, his tactics are anything but simple.

At Milan-San Remo, Cavendish resorted to low cunning, by deliberately losing time on small hills in a previous race, Tirreno-Adriatico, and saying he was only taking part in San Remo for experience. His rivals thought that he would not be able to reach the finish, let alone contest the sprint. They thought wrong, and Cavendish powered over the climbs to become the second Briton ever to win La Primavera and the first in over three decades.

"They thought I wouldn't be able to get over a bridge," Cavendish recalls with a mischievous grin. "These days they have accepted that they can't get rid of me most of the time." It looks as if that will be the case for quite some time to come.

Top Mark: Vital statistics

Born: 21 May 1985, Isle of Man

Height: 5ft 9in

Weight: 69kg

Club: Team Columbia-High Road

Career Highlights:

* Won four stages of the 2008 Tour de France.

* Triumphed in stages four & 13 of the 2008 Giro d'Italia.

* Won the Grote Scheldeprijs in Belgium in 2007 & 2008.

* Only member of 2008 Olympics Cycling team not to win a medal.

Recent Achievements:

* Victorious in the Milan-San Remo in March, winning a tight finish with Heinrich Haussler.

* Won stages two and three of De Panne, a feat he matched in 2008.

* Named overall best sprinter in the Tour of California in February, winning stages four and five.