Cate Spree I guess it's a message of self discovery; growing up and deciding what kind of person you want to be.
This answer contains spoilers… (view spoiler)[I think it's about trying to find your way in life, and how difficult it is to figure out what your way is. During Johanna's first reinvention of herself, she's still trying to define herself according to what others think she should be, or other people's views of what is cool. Who didn't do that at her age?! Eventually, she figures out that isn't working, so she tries another way. We aren't stuck with what we're handed.we can wipe the slate clean and start again. (hide spoiler)]