When Miley Cyrus stopped being Hannah Montana and started her solo singing career, it didn't take long for her to begin behaving in a way that was totally contrary to everything Montana stood for. That didn't happen by accident. Cyrus hated the constraints that being Montana put on her, and when she shook them off, she shook them off with vigor.
Cyrus was a young girl when she first started playing the part that would make her famous, and for many years, she did as she was told. She feels that in the end, being made to look 'conventionally pretty' by makeup artists had a negative effect on her body image, and she eventually became tired of being told what girls are 'supposed' to look like. By the end, she feared she was losing any sense of her true identity. She's definitely recovered it in the years since.