It would not surprise anyone if Spanish tennis star Carlos Alcaraz was humming the tune to an old song while defeating Italian Flavio Cobolli in straight sets in the first round at the French Open.
"When you're smilin', the whole world smiles with you …"
During the on-court interview after the match, three-time Roland Garros champion Mats Wilander complimented Alcaraz on the joy that he brings to the court.
"I've never seen a tennis player at this level that enjoys playing as much as you, that smiles as much you," Wilander said.
"How do you do that? This is serious, this is important."
Alcaraz's face broke into a broad grin, as it often does.
"I try to forget that it is so serious, I try to enjoy it on court. I love playing tennis" Alcaraz said.
And why not?
At 20, he has already won a US Open and reached the top of the world rankings. With 14-time French Open winner Rafael Nadal absent because of injury, Alcaraz could ensure the trophy remains in Spanish hands. The way he has been winning with a smile on his face has inspired his colleagues.
After a first-round victory at Roland Garros, world number five Stefanos Tsitsipas described Alcaraz as "a breath of fresh air".
The Greek star decided during the off-season that he needed to bring the Alcaraz demeanour into his own game.
"The fact that he's so competitive and he's always with a smile on his face — so much charisma to him and so much positive energy that he distributes," Tsitsipas said.
"I have that capacity of being that person, I truly believe that.
"That is also the reason that I'm just much more joyful and happy when playing this sport, due to him."
This was music to the ears of Alcaraz who is yet to lose to Tsitsipas in their four meetings.
He beat Tsitsipas in the Barcelona Open final last month.
"I heard from Stefanos as well that he started to enjoy playing, to enjoy being on court thanks to me and for me it's great to hear that," Alcaraz said.
With 36-year-old Nadal having flagged that next year is likely to be his last on tour, could Alcaraz become the new king of clay?
He was warmly embraced by the Roland Garros spectators during his first match at a major since his US Open triumph in September last year.
"I felt the love from the people, I don't know whether they are Rafa Nadal fans or not but I felt the energy from the crowd," Alcaraz said.
Alcaraz was 10 years old when he first started thinking about becoming a professional tennis player. He idolised Roger Federer and Nadal.
The right-hander with a game for all surfaces rose to prominence when he reached the quarterfinals of the US Open in 2021 as an 18-year-old.
"It's a great feeling to feel that 10 years after, something crazy for me, it's the best feeling in the world to be number one, to know that I reached my dream really quick," Alcaraz said.
Federer won fans around the world with his grace and wide range of shots that evoked memories of a bygone era.
Novak Djokovic's never-say-die attitude has been a key component of his 22 major singles titles, a record he shares with Nadal and could break in the next fortnight.
For almost two decades, the three certainties in life were death, taxes and the Spanish Bull sliding around the red clay, reeling off winners on his way to a French Open triumph.
Alcaraz has only just started his journey but is already developing a following. Whatever he achieves during his career will come with a sense of enjoyment.
His coach Juan Carlos Ferrero often reminds Alcaraz that he plays his best tennis when he is relaxed and having fun.
"It's something I try to do in every match and for me it's the most important thing to enjoy and smile on court," Alcaraz said.