Give it up for Fred and George, the Weasley Twins. That's Fred on the left and George on the right. You know how I can tell? Because I made this picture and arbitrarily decided, that's how.
The Weasley twins love causing touble. If you're friends with the Weasley twins, look out. If you're an enemy of the Weasley twins, LOOK. OUT. One of my favorite moments of the entire series comes when Hogwarts new headmistress/facist dictator Delores Umbridge makes one new rule to many for the brothers to bear. They decide to rebel like never before.
"You two," she went on, gazing down at Fred and George , "are about to learn what happens to wrong-doers in my school."
"You know what?" said Fred. "I don't think we are."
He turned to his twin.
"George," said Fred, "I think we've outgrown full-time education."
"Yeah, I've been feeling that way myself," said George lightly.
"Time to test our talents in the real world, d' you reckon?" asked Fred.
"Definitely," said George.
And before Umbridge could say a word, they raised their wands and said together: "Accio brooms!"
So remember, kids. Next time some adult tries to tell you to stay in school, just tell them the Weasley twins dropped out and went on to be successful small business owners. That's the moral of the Harry Potter series: Drop out of school and you'll be fine.