It is quite an achievement to start the year as the number one tennis player in the world. It's even better to end the same year still on top of the rankings.
And that is exactly the situation in which Novak Djokovic will find himself when he arrives in Abu Dhabi next week for the very last tournament of 2012, the Mubadala World Tennis Championship.
But whether the Serb will even allow himself a moment of satisfaction as he prepares to do battle with Andy Murray and Rafael Nadal is something of a conundrum.
True, the rankings cast him as the dominant force in world tennis. He won six tournaments this year, including toughing out the lengthiest final in Open era grand slam history - a staggering 5hr 53m epic with Nadal in Australia.
Last month, he won a compelling ATP World Tour Finals match over Roger Federer - and when the most decorated player in the history of the game admits "I couldn't have played much better", it would appear to confirm the Serb's status as the man to beat on a tennis court.
And yet it has been a strange year for Djokovic. He lost the French Open final to Nadal. He lost on the grass at Wimbledon in both the All England Championships and at the Olympics.
In the US Open final Djokovic lost again, to his great friend Murray, in a tight, five-set match.
But the failures aren't so much an indication of his fragility as a reflection of his misfortune to play the game in an era marked by four truly great players, of which he is one. Nadal, Federer and Murray can all be unstoppable on any given day. And when they are, Djokovic has learnt not to wallow in bitter recrimination. His five grand slams are proof that there are days when he is similarly unbeatable.
"[Murray] deserved to win this grand slam more than anybody because over the years he's been a top player," Djokovic said after the US Open this year. "He's been so close; lost four finals. Now he has won it, so I would like to congratulate him. Definitely happy that he won it." That he could be so magnanimous after the pain of losing such a close match says a lot about Djokovic. The two have been rivals since they first encountered each other in the junior circuit as hopeful 12- year-olds. But tellingly, they're also great friends.
And the joyful élan with which Djokovic plays the game - as early as 2007 John McEnroe was purring that the then 20-year-old "has so much variety to his game and moves so well" - has won him fans among both the tennis-loving public and his fellow professionals. Such enjoyment continues off the court; before he had even won a grand slam event, he was imitating Maria Sharapova and Nadal in courtside antics that were captured in YouTube clips.
Not everyone liked his attempts at humour but it revealed a young man unaffected by the celebrity circus, and happy to laugh at tennis's absurdities. He was dubbed the Djoker.
So when, this month, it was revealed that Djokovic would own the world's entire supply of donkey cheese it was barely a surprise. The Serb has a penchant for the eccentric. It will be the star attraction of the restaurant chain he is planning for his home country - and apparently it's white, crumbly, and very, very rich.
Such determination to enjoy life's pleasures (which he can afford, as Forbes estimated he earned $20 million [Dh73m] last year) is surely a result of his occasionally turbulent childhood during which tennis was his only escape.
Djokovic's parents ran a creperie, clothes shop and pizzeria in the ski-resort of Kopaonik, in what was then Yugoslavia. Crucially, there were tennis courts opposite the pizzeria, and at the age of 6, Djokovic was spotted at a tennis camp by the coach Jelena Gencic, who had worked with Monica Seles.
"I called to see the father and mother for the first time," she recalled in 2010. "I said, you have a golden child."
It was here that Djokovic honed his game with Gencic, and by the time he was 10, a move to Belgrade was deemed important to continue his development.
But in 1999, Nato bombs began to rain on the city. On CBS's 60 Minutes programme last year Djokovic remembered that "everybody was very, very afraid because, the whole city was under attack".
As his grandfather's apartment building had a basement to shelter in, he lived there with his parents, two younger brothers and aunts and uncles. Under such circumstances, it takes a special mentality to believe in a better future, but Djokovic and his family clearly had it.
"All of us who went through that came out with their spirit stronger," he says. "And now we appreciate the value of life. We know how it feels to be living in 60 square meters being bombed."
The experience made him tougher, hungrier for success, but also less phased by any misfortunes life would throw at him in the future. "I always try to remember those days in a positive, in a very bright way," he said. "We didn't need to go to school... so we played more tennis."
And Djokovic got very, very good at it. Still, leaving home to enrol in a tennis academy in Munich run by the former Yugoslav player Niki Pilic was a big deal for a 12- year-old whose parents were sacrificing everything for the dreams of their son.As Djokovic's uncle Goran recalled in The New York Times, "Of course people were talking sometimes, 'This family is crazy, who do they think they are? How can they even think Novak will be something?'"
But, encouraged by Gencic, they knew that Novak had that indefinable "something". The British, American, French and Spanish juniors enjoyed financial support from their federations. Djokovic just had talent, and desire.
By 2005, he was playing the grand slams as an awkward 18-year-old - his debut a chastening affair in Australia where he only won three games against Marat Safin - but solid performances at Wimbledon and the US Open hinted that a talent had arrived.
Just a year later, still a teenager, he'd broken the top 20, winning two ATP titles and making the quarter-finals at the French Open.
But for all the tour titles and ranking points that would inevitably follow, a tennis player is in the end defined by his grand slam victories, and Djokovic's first came at the 2008 Australian Open.
"I love his head," said Martina Navratilova after his four-set victory. "He's such a smart guy out there and I like his attitude on and off the court."
And that was Djokovic's real USP - he could out-think most of his opponents. Which is why it came as such a surprise that the next slam win didn't come for another three years, as some pundits began to question his fitness and temperament. His answer was staggering.
He opened 2011 by winning the Australian Open for a second time, at the start of a 41-match unbeaten run. Wimbledon and the US Open followed. "It's probably the highest level of tennis that I ever saw," said Rafael Nadal, who lost to the Serb in six separate finals.
So perhaps it is not surprising that Djokovic could not maintain such a high level in 2012. After all, when Pete Sampras called his 2011 season "one of the best achievements in all of sports", such unstoppable form was always going to be difficult to sustain year-in, year-out.
What will Mubadala, and 2013, bring? With Nadal back, and Murray more confident than ever, it's difficult to predict. What is certain is that Djokovic is far from finished. As he told 60 Minutes: "You always try to search for a better life. For something that is better for you and your career." His search - for better tennis, more titles, and, one suspects, more fun - goes on.