An exhibition of letters written by Anne Frank before and during WWII is on display at the Amsterdam Historical Museum through September 3. The Guardian has published a few, including a confrontational letter Frank gave her father — who made the unfortunate mistake of trying to stand between a 14-year-old girl and heavy petting — a few months before the Nazis found the family in hiding.

“All these troubles have made me older; I won’t regret my actions,” she wrote. “I’ll behave the way I think I should! Gentle persuasion won’t keep me from going upstairs.”