I think the Sorting Hat was surprised. I wasn't.
I'm not dark or cunning, just ambitious. With two older brothers and four younger siblings, I have to be. I have to stand out if I don't want to end up being second or third or last place.
My father could have been Minister of Magic. But instead he just plods along in a dead-end job while everyone else takes the credit. He's content to be second-best, second choice for the rest of his life. Fitting, I suppose, since everything we own is second-hand.
I don't want to end up like him, the laughingstock of the wizard community, with a ramshackle house and a family I can't afford to feed. I can do better. My family doesn't understand; to be great, you have to be willing to make sacrifices. Someday they'll realize what I've done for us. People will respect the name of Weasley again, and everyone will know who I am: Percy Weasley, the great wizard and first among his brothers.
My brothers... I love them, but they just don't understand. Ron comes closest, I think. He knows what envy feels like, the icy pit that forms in your stomach when you're regulated to the back. His best friend is Harry bloody Potter, the Boy-Who-Lived. How could he not know? But my baby brother is weak, just like the rest of them. Ron's too afraid of hurting his friend to make a bid for greatness. He's decided to be content with a footnote and a bit of reflected glory. I don't understand how he can bear it. That's not enough for me, could never be enough for me.
The Sorting Hat asked me where I wanted to go: Gryffindor or Slytherin. Of course, what I wanted was to go back home to Mum and Dad and Ron and Ginny and the twins and forget all about Hogwarts and magic and how, on the train, Marcus Flint had called me a dirty Muggle-lover. I was eleven, and scared, so I told the hat that I'd like to be with my brothers, and it stuck me in Gryffindor.
I was an idiot.
I could have been in Slytherin. But now it's too late. It's too bad, really.
Among the Death-Eaters, Gryffindors are always second-best.