The French superstar looked nailed on to leave PSG this summer, with his contract due to expire at the Parc des Frances.
Mbappe was reportedly on the verge of signing for Real Madrid on a free transfer.
However, the World Cup winner had a change of heart and signed a three-year contract on Saturday - the same day as when he hit a hat-trick against Metz.
Mbappe is in line to earn a ridiculous wage of €100 million per year, while there's talk that his new deal gives him a say in the next manager, and will see him assume captain and penalty duties.
On Monday, PSG held a press conference with Mbappe, who opened up on changing his mind.
"Everybody knows I wanted to leave last year, and I was convinced that would be the best decision at that time," Mbappe told media.
"The years pass but they are different and the context is different now. That goes for sporting terms and also, personally, I was free to make a decision, and I know how important that is in France.
"It is the country where I have grown up. I have always lived here, and leaving my country wasn't the right thing.
"There is a sentimental aspect to his. It is my country.
"The sporting project has changed as well. That made me want to stay because I don't think my story is over yet.
Mbappe did also send a message to the Los Blancos fans who thought they would be seeing him in their colours next term.
Mbappe added: "Message to Real Madrid fans? I wanna say thank you, as they always accepted me as one of them.
“I understand their disappointment, and I hope they understand I decided to stay in my country."
🗣 "I don't think my story is over yet."— Football Daily (@footballdaily) May 23, 2022
Kylian Mbappe explains why he changed his mind about leaving PSG pic.twitter.com/KVkCt099Y6
Mbappe finished the season as Ligue One's top scorer for the fourth consecutive season after hitting 28 goals.
His PSG tally currently stands at 168 goals and a further 33 strikes for the club will see him usurp Edinson Cavani as record goalscorer for the Parisians.
Spanish TV show El Chiringuito claim Mbappe told Real president Florentino Perez his decision via WhatsApp, his message reading: "I'm communicating to you that I have decided to stay at PSG.
"I want to thank you for the opportunity you gave me to play at Madrid, the club I was fan of since I was a kid."
Featured Image Credit: Image: PA & PSG
- Captain for PSG's next opponents is one of their ultras, he's worried about injuring Kylian Mbappe
- Kylian Mbappe ruthlessly scores five goals past sixth tier side Pays de Cassel
- Kylian Mbappe produced hilarious reaction to Neymar’s free-kick during PSG warmup
- The Numbers Behind Kylian Mbappe's Mooted New Paris Saint-Germain Contract Are Mindblowing