The fruit of a sportsman's talents and labours can be great – trophies, money, adulation and a lifestyle that most look at with envy.
But for some, no matter how many rivals they beat on the field of play, one opponent they can never overcome is themselves.
In an introspective interview that is a rarity among the media-trained sporting elite, France's world number 10 tennis player Jo-Wilfried Tsonga said on Wednesday that he finds it hard to enjoy his achievements, and that he is trying to kick his habit of "self-flagellating."
I do not tell myself, ‘It's fine, continue to work, one day you'll get there.' No, what I hear from myself is that I am a wasted talent.
It came after a hard-fought win over Nikolay Davydenko as he opened his Marseille Open title defence on Tuesday, and which followed a soul-searching session with his coach in Rotterdam the week before in which Tsonga repeated the mantra, "Jo, life is beautiful."
"He (coach Thierry Ascione) is trying to make me mindful, and to learn to look at things relatively," Tsonga told the L'Équipe sports newspaper.
"Basically, there is always a war within me, and I find it hard to relax."
The problem came to a head after the 28-year-old's second-round exit to Marin Cilic at the Rotterdam Open, when Ascione said he could tell there was "something profound" the matter with Tsonga.
After "flaying himself" on court every time he made an error on the way to a 6-4, 6-4 defeat, the Frenchman and his coach came to the conclusion that Tsonga – who rose to number five in the world in 2012 – was allowing himself to become a victim of his own ability and potential.
"When I look at it now, it is because to be number 10 in the world, for me, is not good," Tsonga said.
"I do not tell myself, ‘It's fine, continue to work, one day you'll get there.'
"No, what I hear from myself is that I am a wasted talent."
An inability so far to win a Grand Slam may be cranking up the pressure – although it's something that other players such as Caroline Wozniacki seem to be able to brush off, at least by outward appearances.
The Dane told Al Jazeera last week that having been women's world number one for two years earlier this decade was "a pretty good effort", and saw the elusive Grand Slam as a challenge rather than as a sap on her morale every time she failed.
Tsonga compared his own "negative climate" with Stanislas Wawrinka, who had been on the circuit for years before winning a surprise Grand Slam by beating Rafael Nadal in January's Australian Open final.
"I watched his progression, then his metamorphosis," Tsonga said of the Swiss who rose to world number three after his triumph – which was also the first time a Grand Slam had been won by a non-Federer, Nadal, Djokovic or Murray since 2005.
"But with him, you could never say that he was about to hit his top level very soon. As a result, he got there calmly and he did his thing.
"Of course, I am impatient and I want to get there tomorrow, but I have to be clear-headed. Tennis is not magic."
Paul Rhys is a freelance sports reporter and presenter writing for Al Jazeera from Paris. Follow him on @PaulRhys_Sport or go to paulrhys.com.
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