Why did the ghost girl finally regain her memory?

Because Chi Enzhuo was reincarnated with a memory, and that memory has always been there.

The end of ghosts is that lovers get married. In the last scene, Chi Enzhuo reincarnated with memories and found Jin Shu in Quebec. This is still a beautiful picture of playing with dandelions. The two smiled at each other and finally didn't miss each other in this life. Netizens found that when the first episode met in the rain, the fragment that the ghost saw was the ending.

Related information:

Under God's arrangement, ghosts wander alone between the absurdity and falsehood abandoned by God. Nine years later, 29-year-old Chi Enzhuo blew out the candle on the day of the first snow and called back the ghost. I can summon again in nine years.

First, it was written in their contract that Party B would be called away by Party A on the day of the first snow, and second, because the messenger of the underworld said that 9 was the closest number to God. Chi Enzhuo met the Hellscream at the age of 9 19, but at the age of 29, the reunion with the ghost seemed to end his life.