1. A fan's way of letting a story they love continue on by creating a new story in the same world.
2. A fan's way of saving their favorite characters, fixing thing's they don't like in the plot, and pairing up characters that have nothing in common, were never supposed to be together, and have zero chemistry.
3. Your English teacher's worst nightmare.
You: Hey, I just wrote a fanfiction that continues on Harry Potter's life after Hogwarts.
Friend 1: Awesome! I wrote a fanfic where Darth Vader turned out to be a good guy!
Friend 2: I wrote a fanfiction where Katniss and Peeta weren't in the Hunger Games.
Your worst enemy: I wrote a fanfic where Edward fell in love with Jacob.
Worst enemy's English teacher: DETENTION!