Novak Djokovic, who won a record-equalling 23rd Grand Slam title on Sunday, is driven on through controversy by his determination to be the greatest ever.
The Serb's victory over Casper Ruud in the French Open final took him past great rival Rafael Nadal at the top of the list of all-time men's major champions.
For 36-year-old Djokovic, it matters to be the best, and he has a strong sense of his historical place in tennis.
But he also keeps ploughing on through the highs and lows because it is "a great school of life".
While Nadal and now-retired Roger Federer are widely admired, Djokovic continues to divide as well as unite.
His staggering achievements on the court have often been overshadowed by blunders and missteps off it.
The latest was in the first week of the French Open when 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, he was booed for fist-pumping as semifinal rival Carlos Alcaraz wilted with cramping.
"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 last year 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 the US Open.
Even before that, the Serb was seemingly doomed never to be held in the same 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.
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.
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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 23 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 No 1 for the first time.
In total, he has 10 Australian Opens, seven Wimbledons, three US Open titles and now three French Opens.
He is the only man to have won all four majors on at least three occasions.
And time appears to be on his side in the quest to be considered the greatest of all time.
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 shows few signs of losing his physical edge – 11 of his 23 Grand Slams have come after he turned 30.