You know your a Harry Potter nerd when you make your own book using every single spell created by J.K. Rowling, then roll up paper as a wand and cast spells at family members when they're not looking. (hey it's really fun when you're really bored!)
You know when your HP fan you start speaking in a British accent and start speaking like the characters, eventhough you're American.
It's obviously happened to me. I still can't controll it.whee
Oh my... I can relate to this one too. I just discovered it yesterday when I said, "Mum, I'm going for a walk." in a perfect British accent. Also a couple friends and I talked like that all day. It drove the teachers mad.