Braceface - Season 3 Episode 10 Identity Crisis
Overview: Sharon is feeling dull, ordinary and unadventurous. And worst of all, her friends see her that way, too. So when a quirky substitute-student teacher encourages Sharon to be more free-spirited, Sharon embraces a new spontaneity. But as she grows closer to the teacher she begins to alienate her friends. Soon she learns that it's a fine line between being free-spirited and eccentric.