Must we read letters from our past selves?

My daughter wrote letters to her future self when she was about 8 years old. She had noticed that perfectly nice kids sometimes turn into grumpy teenagers, and she wanted to tell herself not to do that. Now that she's 15, she refuses to read these letters. She thinks her 8-year-self has nothing to teach her.  Possibly cute, but something of a dolt -- I think that's about how she sees her past