New York: Novak Djokovic, who won his fourth US Open and all-time record-equalling 24th Grand Slam title on Sunday, is driven on through controversy by his determination to be the greatest ever.
The Serb's victory over Daniil Medvedev at Flushing Meadows - his third major triumph of 2023 - took him two Slams clear of great rival Rafael Nadal at the top of the list of men's Slam champions.
For 36-year-old Djokovic, it matters to be the best, and he has a strong sense of his historical place in tennis.
He also keeps ploughing on through the highs and lows because it is "a great school of life".
"I would like to send a message to every young person out there. I was a seven-year-old dreaming that I could win Wimbledon and be world no.1 one day," he has said.
"I am beyond grateful but I feel I had the power to create my own destiny. I believe it and feel it with every cell in my body. Be in the present moment, forget about the past. If you want a better future, you create it."
Yet while Nadal and now-retired Roger Federer are widely admired, Djokovic continues to divide opinion.
His staggering achievements on the court have often been overshadowed by blunders and missteps off it.
At the French Open this year, he wrote "Kosovo is the heart of Serbia" on a courtside TV camera lens as ethnic tensions were again rising in the Balkans.
On court at Roland Garros, he was booed for fist-pumping as semi-final rival Carlos Alcaraz wilted with cramping.
Djokovic remains indifferent to the critics.
"I don't mind. It's not the first; probably not the last. I'll just keep winning," said Djokovic.
His most controversial moment was his refusal to be vaccinated against Covid, which culminated with Djokovic being deported from Melbourne on the eve of the 2022 Australian Open.
His uncompromising stance on the vaccine also saw him barred from the United States and unable to play in last year's US Open.
Even before that, the Serb was seemingly doomed never to be held in the same saintly esteem as Federer or Nadal, the undisputed people's champions.
There are those who see something too calculating in the Djokovic make-up - an intense, brooding presence prone to affectation.
His infamous default from the US Open in 2020 for petulantly swiping at a ball that hit a female line judge gave a glimpse of his fiery character.
I don't mind. It's not the first; probably not the last. I'll just keep winning
And some of his personal stances have drawn criticism - one claim that raised eyebrows was his belief that it was possible to alter the composition of water and food through positive thinking.
Date of birth: May 22, 1987
Place of birth: Belgrade
Professional debut: 2003
Career earnings: $169,791,880
Highest ranking: 1 (388 weeks in total from Monday)
Total ATP titles: 96
Grand Slams: 24
Australian Open (10) - 2008, 2011, 2012, 2013, 2015, 2016, 2019, 2020, 2021, 2023
French Open (3) - 2016, 2021, 2023
Wimbledon (7) - 2011, 2014, 2015, 2018, 2019, 2021, 2022
US Open (4) - 2011, 2015, 2018, 2023
ATP Tour Finals (6) - 2008, 2012, 2013, 2014, 2015, 2022
Davis Cup (1) - 2010
Year ending world number one (7) - 2011, 2012, 2014, 2015, 2018, 2020, 2021
However, the career achievements and resolve of a player who was the first to smash through the $150 million prize-money barrier cannot be doubted.
Djokovic, who left Belgrade when he was 12 to train in Munich and escape NATO's bombardment of his home city, captured the first of his 24 majors at the Australian Open in 2008.
It was three years before he added his second.
He dropped gluten from his diet, his lithe physique allowing him to chase down lost causes, transforming him into the rubber man of tennis with a rock-steady defence.
In 2011 he enjoyed a spectacular year, winning three of four Slams and becoming world number one for the first time.
In total, he has 10 Australian Opens, seven Wimbledons, four US Open titles and three French Opens. He is the only man to win all four majors at least three times.
His collection of 39 Masters titles is also a record as is his 389 weeks spent as world number one.
And time appears to be on his side in the quest to be considered the greatest.
Federer is retired now while Nadal, 37, is sitting out the rest of the season due to a hip injury which might well see him permanently sidelined.
Djokovic also shows few signs of losing his physical edge - 12 of his 24 Grand Slams have come after he turned 30.