The other boys used to laugh at the way Kylian Mbappe ran down the wing. Not in a malicious way, and not with any intention of upsetting him, but simply because it was so unusual. They would stare, giggling to themselves, as the young Mbappe, with his elongated limbs and oversized head, appeared to leave his left arm behind every time he broke into a sprint.
As the rest of his body flowed, that left arm extended and locked into position. It would jut out like a sail, hanging away from his torso, and whip across his chest with each stride.
Watch him now, five years later, and the kink is harder to spot. Those arms have become swollen with muscle, and the legs pump with such speed that you would need a slow-motion camera to make out anything more than a blur of blue.
As his traumatised opponents at this year's World Cup will attest, Mbappe's running is not so funny any more. It will instead be a source of fear in Croatia, where knees will tremble from Zagreb to Dubrovnik on Sunday as Mbappe becomes the first teenager since 1982 to play in a World Cup final.
By sundown in Moscow, the 19-year-old may have been named the tournament's best player. France could be World Cup winners, and Mbappe would be fully anointed as the successor to Lionel Messi and Cristiano Ronaldo as the game's next great superstar.
Looking on from Paris, 1,500 miles away, the boys who once laughed at his erratic arm will be shaking their heads in disbelief. It was only four years ago, as the previous World Cup came to an end, that Mbappe was still one of them, a skinny lad nicknamed "Peanut" who was learning the game at the fabled Clairefontaine academy. He was not even the best player there.
How, they will ask themselves as Mbappe's face adorns big screens across the country, did this happen? "We saw the player he could be," says Allan Momege, who lived with Mbappe at Clairefontaine from the age of 13 to 15. "We just did not expect it to happen so quickly."
The Mbappe story begins in Bondy, a troubled town in the north-eastern suburbs of Paris. His mother, Fayza, was a former handball player, while his father, Wilfried, worked as a football coach at the local club, AS Bondy. From the age of two, little Kylian would follow his dad to work, sitting in on team-talks with a ball under his arm.
Nearly two decades later, Mbappe's face decorates an enormous banner behind the club's artificial pitch. "Merci Kylian," it says. The little club will be flooded with people on Sunday as it shows the final on a giant screen, but it has become used to hosting visitors: every day, someone else comes looking for the place where the boy wonder first learned to play.
What is less well-known is Mbappe's time at Clairefontaine, the secluded national football centre in the Rambouillet forest, 30 miles to the south of Paris. It was here that he went from raw to refined, from boy to man.
"At the beginning it was complicated for him," says Samy Hammour, who played alongside Mbappe at Clairefontaine, which recruits 23 players every year and trains them from the age of 13 to 15. "Physically he was always very thin. He had all the qualities, but he was not strong and grown up."
Other boys were better, but few enjoyed life in Clairefontaine as much as Mbappe, who gave as good as he got when he was mocked for his running. "He was always laughing," Hammour says. "He used to tease - he always had a little word to say."
Mbappe would be at the centre of the impromptu kickabouts in the bedrooms at night, when they would play with a soft ball through fear of being caught by the Clairefontaine staff. "He used to get in trouble a lot," Hammour says, smiling at the memory.
At this age, he also had a habit of smashing a ball towards goal before warming up. He knew it angered his coaches, and he would deliberately wait until their backs were turned before doing it. "He was one of the clowns," says Momege. "He had to do extra studies in the evenings because he was always clowning around in class."
For all his exuberance, Mbappe remained discreet about his career prospects. As he began to fill out, to develop those muscles and to catch up with the other boys, he would be inundated with interest from professional clubs. He supported Real Madrid, and loved Ronaldo, but told only a few of his friends that he had been invited by the club to Spain. "That was out of kindness," Momege says, "because some of the others did not have a club."
Hammour remembers returning to Clairefontaine late one Sunday night to find boxes of brand new football boots lying in the hallway. There was a note on top, telling the boys to help themselves. They were a gift from Mbappe, who had evidently agreed a sponsorship deal with a major sports brand, but had never spoken about it. Hammour, who eventually chose to study medicine rather than pursue football, still wears them now.
Upon graduating from Clairefontaine, where Mbappe had begun to thrive only in the final six months, it was decided that Monaco would provide the best environment for him to develop. Gangly and fresh-faced, he made his debut at the age of 16 years and 347 days, beating Thierry Henry's record to become the club's youngest ever player. The following season, he scored 26 goals in 44 matches.
The hype was building, but it was only last year, once Paris Saint-Germain had agreed to pay £165 million for an 18-year-old, that the madness really begun.
The paparazzi arrived at his family home in Bondy as soon as the deal was done. Mbappe grew up on a private road rather than in the Bondy slums, and the photographers would drive down every day, looking for an exclusive that never came. The Mbappes no longer live there, but it was only in March, seven months after he joined PSG, that the cameras finally left.
"He used to play in the street," says Alain Duchesne, Mbappe's former neighbour. "He would play with my three grandchildren, but I think it was only to be nice."
Duchesne remains in contact with Mbappe's mother, Fayza, who is the guiding force behind the prodigy's career. Momege jokes that Mbappe was terrified of his mother, adding that it was always Fayza who would talk to the other parents at Clairefontaine. Wilfried, ever the coach, would silently analyse his son from afar.
Fayza has since avoided the limelight, making a deliberate effort to stay out of the pictures when Mbappe was unveiled at PSG. She is known, though, in Bondy, where the Mbappe name has become synonymous with hope and success in a town that has not had either for a while.
"We needed something good here," says Jean-Jacques Dougal, a butcher in the centre of Bondy. "There used to be these kids that tried to steal from me. Fayza was here once when a kid tried it. She stopped him, gave him €2 and told them to leave me alone. They knew she was Mbappe's mother. I have not had a problem since."
The reputational boost for the area has been dramatic. Before, Bondy was best known for being one of the centres of unrest in the 2005 French riots, and for its high levels of unemployment. Now, it is famous for being the place that forged Mbappe. The hope is that his rise will continue to change perceptions, yet the reality of modern football is that, with each passing day, he gets pulled further and further away from his roots.
Mbappe is no longer little Kylian. He is a commercial entity, a brand. His image is so carefully cultivated and his words so sensible that he has been nicknamed "little Obama". In February he even had lunch with French president Emmanuel Macron, where they discussed funding for sport in Africa. If he stars in the World Cup final, one can only imagine how much more of this there will be in his future.
It was already difficult, before the World Cup, for Mbappe to remain in contact with his old Clairefontaine friends, or to return to the streets of Bondy. "All of those memories in life that you can tell your children, I don't have those," he said last year. "When my kids ask me, 'what did you do when you were 18?' I will tell them I was already a star and had to stay at home."
They know this at AS Bondy, where dozens of boys are playing on a small-sided pitch. Some love Mbappe, but others prefer Neymar, his PSG team-mate. They are all wearing football shirts at Mbappe's old stomping ground, but not one of them has his name on their back. "It costs too much" one boy says, a little glumly. "And if he wins the World Cup, it will become even more expensive."
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