When I was 10 I found my Mom reading my journal. I was pissed 100% off and got rather mad. She literally did not understand what she had done and I could never explain it to her. It was then I realized the idea of privacy meant to NEVER have any way for her to ever know something - so I could not put it on paper.
Also there where many times when she asked me about something and I would say "you don't want to know" - I would NOT say this twice as there was literally no point. She ALWAYS wanted to know and most of the time when I told her she was horrified or it shattered he illusion of who I was and she would say "you are right, I did not want to know". YET, every last time she would say "I want to know".