What is the short message in Lin Beixing's mobile phone draft box?

The one deleted before was sent to Yu Zhan herself, and the last two were sent to her by Zhang Wansen, with unknown recipients.

Lin Beixing, a senior girl who is about to turn 30, was broken up by her long-time boyfriend Yu Zhan, and her life and work became a mess.

I don't know whether it is the favor of the gods or the call of the old man in time and space. Lin Beixing recalled the past with her old mobile phone, but unexpectedly found that she could return to high school by deleting short messages.

Lin Beixing tried to seize this opportunity to rewrite his destiny, only to find that every time he went back to the past, the evening after the college entrance examination would be sent back to reality, and it was this man named Zhang Wansen who broke his dream.