Students of Nanjing University spend their birthdays with a message from their mother. The story behind it is that the students' mother is a frozen patient and needs to be taken care of. They used to take care of their mother every day when they were around, just as her mother took care of him when he was a child. After finishing college, she will leave her mother to study abroad and can't stay with her. Her mother dictated some words to her college classmates. What moved her most was that her mother loved you very much. These oral letters inspired her.