We left him in Moscow a bit more than four weeks ago, lifting the World Cup at only 19, scoring in the final and being named best young player of the tournament -- four years after his teammate Paul Pogba won the same accolade. Kylian Mbappe was on cloud nine then, in dreamland.
He was heralded before the start of the tournament as the next big thing, as the most promising talent of his generation -- and of the one before and probably of the next one, too. And he delivered.
He remained quite discreet in the celebrations back home. We soon saw photos of him enjoying his holidays in Ibiza. We noticed how his status of rising star had already been trumped by the status of big star. We could see all the Mbappe shirts on every street corner in Paris and throughout the rest of France. His name was on everyone's lips, in all the conversations. The Parisians clearly had entered a new dimension.
However, there were still questions asked.
How will Mbappe deal with his new popularity? How will he cope with expectations? How long will it take him to get over the World Cup, physically and mentally? Without forgetting the new dynamic of his relationship with Neymar and working with a new manager in Thomas Tuchel.
We found Mbappe again on Saturday in Guingamp.
He didn't feature in PSG's first league game of the season at the Parc des Princes against Caen the previous weekend, a comfortable 3-0 win. He wanted to at least be in the squad, but Tuchel left him at home. This time, he was on the bench. He came on at half-time and changed everything. In the space of 45 minutes, he rescued his team, "like a messiah" as was written on the front page of L'Equipe. He scored two goals to win the game for the champions and was unstoppable. His hunger was remarkable although logical after a month without competitive football. Still, he looked fresh, full of desire and energy.
He also answered some of the enquiries. He clearly has not suffered any World Cup hangover.
"The World Cup? It's finished. We won it, it is part of history. But now we are all back at our club," he said after the game on Saturday. "I haven't won everything. There is still a lot to win, be reassured."
Mbappe is like a machine. What happened in Russia was clearly only just the beginning. He has been playing first-team football for 18 months so far and he has won two French league titles, one French Cup, one French league cup and the World Cup. All of this before even earning his driving licence. But he wants more, and he is ready for more.
In Guingamp, we have rarely seen so many home fans waiting after a game for a player from the opposition. But children cried after they saw Mbappe, after a selfie with him or a quick autograph.
"My work is still the same, whatever my status. It is not a problem," he explained on Saturday, unfazed by the circus around him. "All I want is to score and to win. I am working to produce this kind of performance and I am working to do it again next week."
It is a bit too early to say how Tuchel will use him through the season. On Saturday, he came on for Timothy Weah as a centre-forward. He had Neymar on his left and Angel Di Maria on his right. He had 32 touches in just 45 minutes and only one in his own half. However, when Edinson Cavani is back, Mbappe will surely go back wide. It will be interesting to see then how he plays.
Tuchel might want him, and Neymar, a bit more inside, almost as second strikers, than staying too wide too often. A lot of experts see the Frenchman's future as a No. 9, and maybe Tuchel will try to get him to play closer to Cavani and to the opposition's goal.
On Saturday, Neymar assisted on Mbappe's second goal and their relationship seems as effective as ever. They are often together at training and you can see the chemistry between them when they play. For Mbappe, things are pretty simple: World Cup winner or not, best young player of the tournament or not, he is at Neymar's service.
"Our relationship is not going to change. Things are very clear between us and the manager confirmed it too," Mbappe said in Guingamp. "Neymar is our leader and we are trying to help him. OK, [Saturday] he helped me, but I will try to help him in the coming weeks."
For now, Neymar is still the king and Mbappe the prince. But the start of the season has showed already that things could change very quickly.