If you don't know who Mia Thermopolis is, you're lucky. She is the bratty teenage character in The Princess Diaries that finds out she is a princess and literally gets pissed at everyone for no reason. Just a few things come to my mind when I think about her.
First of all, when she initially found out she was a princess, she flipped her lid completely and yelled at her mom for "lying" to her for fifteen years. Excuse me, but if I found out I was a princess I would think it was really super dope and just accept it. Second of all, her behavior is so unladylike. I get that she's only 15, but she acts like she's seven. Why in the world would you just automatically run through the grass when you get to your long-lost grandma's fancy house? And why would you try to hold hands with a a statue, break off its finger, and then stick it back in the statue's mouth? That is so random and weird. Not to mention how blatantly rude she is to her grandma, queen of Genovia. Saying "shut up" in one of your first conversations with her is just impolite. Chill. I know that she was taking "princess lessons" to learn to act like a princess, but she really just needed lessons on how to act like a decent human in public.
She also received a princess makeover, which was so fake in my opinion. Not because she got the makeover, but because she had no desire to change, until someone told her to. Don't even get me started on how "ashamed" she was to take off her hat in class. You are fake; just own it.
Mia is also a horrible judge of character. She ignores Michael, the sweet, guitar-playing boy, for this tan-piece-of-garbage, Josh. And when she realizes that Josh was actually only using her because she was a princess, she felt bad for Micheal and sent him a nasty pizza. Thanks Mia!
All in all, Mia Thermopolis gets slightly less terrible by the end of the movie, after being taught to behave like a normal human, but let's face it, she will always be horrible because she is played by Anne Hathaway. Zing