why didnt uncle henrik tell annemarie more about the lie?

When Annemarie asks Uncle Henrik about Great-Aunt Birte, she is angry that he lied to her. Later, Uncle Henrik explains that he only lied because it will be easier for Annemarie to be brave if she does not know everything. At first, Annemarie does not understand this, but then she thinks back to the day that she and Ellen were stopped by the German soldier on their way home from school. It would have been harder for Annemarie to answer the soldier’s questions if she had known at the time that the Germans wanted to take the Jews away. After thinking about this, she realizes that Uncle Henrik and Mama are just trying to protect her.