What did Sophie find in one of her notebooks at school?

What chapter are you referring to?

She found a postcard from Lebanon from Hilde's daddy

In "Sophie's World" by Jostein Gaarder, Sophie discovers a note in one of her school notebooks. This discovery marks a pivotal moment in the story. The note is a philosophical message from Alberto Knox, her mysterious mentor. It reads:

"Who are you?"

This question prompts Sophie to begin her philosophical journey and sets the stage for her exploration of fundamental questions about identity, existence, and the nature of reality. It's a key turning point in the narrative, as it leads Sophie to question the nature of her own existence and to delve into the world of philosophy.