Why Kylian Mbappe left his old club PSG is unknown to me.
Do you only know about football and Mbappe today or recent months?
The player had many drama in PSG and in several latest seasons, many times he shown his intention and told it publicly on media that he wanted to join Real Madrid, because it is a favorite club in his heart since he was a child.
I tried searching for it but failed to find it.
You did not search enough.
I was kind of shocked by his decision.
Not shock at all if he wanted to leave PSG for years and eventually he did.
Because there was a bright future for Kylian Mbappe at PSG which can be deduced from the old stats.
PSG gives him a bright future many years ago when he was about 17 or 18 years old with a transfer from AS Monaco to PSG, but when he already became a world class player, he saw no bright future with PSG, and he found it at Real Madrid where he wanted to move to.