Olive's parents (played by the ever popular Stanley Tucci and Patricia Clarkson) steal every scene they are in due to being both hilarious and lovable.
Mr. Griffith gets some love too for being a cool teacher.
It's agreed by some of the fandom that Olive, like her brother, was adopted.
Alternately, it's also believed that Olive and her unseen older brother are their mother's biological children and their father is their stepparent.
Marianne being a closeted/repressed lesbian or bisexual and having a crush on Olive.
Genius Bonus: The foreign film that Olive goes to see using her free tickets, and whose name she has trouble pronouncing, is not just the German translation of "The Scarlet Letter", but is actually the 1973 German adaptation of the novel.
Harsher in Hindsight: Amanda Bynes' character is a clean-cut, Holier Than Thou Christian fundamentalist. Since this movie, Bynes has become better known for her drunk driving charges, traffic accidents, disgusting and disturbing Twitter rants, and generally bizarre behavior than she is for her acting. The fact that this was the last film she did before her sudden meltdown doesn't help matters. It makes her "seems as if someone's going on a downward spiral" quote more painfully ironic.
He Really Can Act: Dan Byrd, playing Brandon. The speech he has about how hard it is to be gay really shows off his acting skills.
Hollywood Homely: Subverted. Olive speaks about her lack of allure, being invisible to members of the opposite sex, and how she has never been the sexual desire of anybody, which would come off as hard to believe given Emma Stone's beauty, but the eventual point of the movie is that it all revolves around image and perception. She was never supposed to be physically unattractive, just viewed that way as a result of her High School status.
Informed Wrongness: It's presented as a Kick the Dog moment for Olive when she tells Mr. Griffith his wife is cheating on him, but she’s absolutely right to do that, especially since Mrs. Griffith is not only cheating on him with a student, but also has chlamydia and is keeping it a secret from her husband (which could easily get him sick, as well) and forcing Olive to keep quiet while spitefully claiming no one would believe her if she came clean.
Iron Woobie: Olive definitely qualifies. At one point in the film, her fellow students, including her erstwhile best friend are picketing at school with placards calling her a whore, and she still keeps her head up. And when she tells Mrs. Griffith "I could have chlamydia," you want to give her a hug and stand up and salute her. It Makes Sense in Context.
Marianne frequently comes across as a repressed lesbian who is attracted to Olive. At one point she actually sniffs Olive's hair.
Rhi and Olive as well. In the original script, it even says Rhi has had a crush on Olive since grade school.
Memetic Mutation: Emma Stone exclaiming "Yum!" during the Lobster Shack scene became a popular gif, due to her cross-eyed expression while saying that.
Questionable Casting: The girl picked to play young Olive looks absolutely nothing like Emma Stone.
Brandon, Olive's friend who is bullied for being gay. His "We can talk about how things will get better all night long, but right now this sucks!" speech was especially heartbreaking in light of the multiple gay teen suicides around the time the movie came out (fall 2010). He gets his happy ending though.
By about halfway through the movie, Olive herself. In the attempted rape and confessional scenes, you just want to reach through the screen, give her a hug, and tell her it'll all be okay.
