THE story of the rise of Novak Djokovic is one of sudden, dramatic injuries, turbulent family circumstances, and failed romantic hopes in Glasgow.

It is served with a box of chocolates and some donkey cheese.An explanation is needed. The 25-year-old Serb returns to Melbourne to defend his Australian Open title as the best player in the world, but his ascent to the top has been marked by stumbles, even falls.

When he won the Australian Open in 2008, Djokovic looked as if he could break the duopoly being forged by Rafael Nadal and Roger Federer. Instead, it took him three years – until his fabulous season of 2011 – to frank his talent with a glut of Grand Slams.

He bids for his sixth next week with Nadal on the sidelines and Federer no longer his nemesis. The gangling young man with the boundless energy of a puppy and an unrefined humour that irked the more sedate Federer has now become the charming, articulate world No 1.

And this brings in the box of chocolates and the donkey cheese. The latter is, apparently, a business venture for Djokovic who owns a restaurant in his homeland; he has made a deal with the only farm in the country that produces the product.

"It is not completely true that we bought the whole supply of donkey cheese, even though it is the first time in my life that I heard that donkey cheese exists," Djokovic said, addressing the matter of crucial significance in the build-up to the Australian Open.

"There is a certain farm in Serbia that produces this donkey cheese and, as I understand it, it is the only farm in the world, which is very interesting,'' he added with the forbearance that marks the recognition that his status now comes with the burden of addressing queries that are far removed from the status of his forehand or the strength of his second serve.

Djokovic has assumed this role with grace and charm. At the 02 Arena in London in November, he presaged his victory in the tour finals by personally handing out chocolates to the press after talking with dignity of the illness of his father Srjdan, who was suffering from respiratory problems.

This ability to handle personal crises has been learned through experience. Djokovic lost his way before finding the No 1 slot. In the summer of 2010, he was looked upon as an under-achiever, an inconsistent player who had got lucky with winning a Grand Slam after playing a final against Jo-Wilfried Tsonga, not Federer or Nadal. Federer had been his nemesis in Grand Slam semi-finals, but more importantly Djokovic was gaining a reputation for physical frailty. The Serb has always claimed he suffered from breathing difficulties, exacerbated by allergies. This difficulty, he has since said, has been solved by adopting a gluten-free diet.

But opposing players, particularly the best ones, sensed there was a fragility that went beyond the physical. Djokovic gained a justifiable reputation as a player who pulled out of tournaments during matches. Andy Roddick once accused him of suffering from a list of ailments that included "bird flu, anthrax, SARS, common cough and cold".

His woeful defeat to Tomas Berdych in the Wimbledon semi-final of 2010 convinced the most sympathetic observers that Djokovic was destined never to fulfil his extraordinary potential.

Yet the player has become the fittest, most resilient performer in the sport. His Australian Open semi-final against Andy Murray and final against Nadal added up to more than 11 hours on court.

But there were still other bumps on the road. He was badly affected by a slump in form that accompanied his decision to change his serve, he was stretched emotionally by the break-up of his parents' marriage and he had to adapt to the changing demands made on him.

Immersed in tennis, a bond he shares with Murray, their friendship stretching back to the days when they played an under-11 tournament together, it is no ordinary life and it makes strange demands. This devotion to the sport is necessary if one wants to become the best, but it stunts growth in other areas. It is difficult if not impossible to gain a coherent world view when one is constantly on court, practising or playing, or sitting in a metal tube hurtling towards the next tournament.

But Djokovic has grown from the boy who played at the Braehead Arena in 2006 and who, after helping to beat Team GB, wandered into Glasgow's Merchant City where he made a series of unsuccessful attempts to chat up a table of local young women. At 18, he was unrecognised and unloved by the wider world.

Now he is the leading man in a drama that captures a huge global audience. He is in a long-term relationship with Jelena Ristic and he knows how to throw the press a bone, muttering on at Wimbledon about his poodle Pierre who has, inevitably, a Twitter account and detailing his holiday at Gleneagles with a stop at Murray's home town of Dunblane.

More cleverly, he keeps intrusion at a distance. The mandatory press conferences are dealt with efficiently, but access to him is limited and he fields questions with an increasing maturity.

Djokovic has earned more than $45 million in prize money and tens of millions in other deals. His extra-ordinary year of 2011, when he went on an unprecedented unbeaten run and won three majors, triggered bonuses that his apparel sponsor, Sergio Tacchini, could not afford. The two parted ways in May and Djokovic signed a deal with Uniqlo.

Intriguingly, Djokovic believes 2012, when he won only the Australian Open of the four majors, was his most successful season.

"I feel even more satisfied right now than last year, even though I had an incredible 2011," Djokovic said in London after winning the tour finals. "I feel this year, considering the circumstances that I had to face on and off the court, expectations, all these things, I believe this year has been even more successful for me."

These were the words of someone who has lived a compelling story but believes there are thrilling chapters to come. The narrative continues in Melbourne this week.