Several students from the East boarded the train and embarked on a magical day of no return.
"Hufflepuff"
"Ravenclaw"
"Gryffindor"
"Slytherin"
They will put aside the boundaries between colleges and the discrimination of blood, become friends, and become a part of each other's lives.
They are a symbol of friendship.
When they graduated, they gave each other a message:
"Don't worry, no one knows you in the future. No one in the world knows you."
I haven't read the original book yet, so I used the movie as a reference.
Purpose: Don't worry if you have no friends in the future, no one in the world will know you.