When you are at school and can't be stuffed doing anything except read Deathly Hallows, so you pretend to be sick so you can go home and spend the rest of the day reading the book.

When you knitted a Gryffindore scarf!

-when you think all of the above mentioned things are normal and should not be frowned upon.
-when the biggest fight you've had with your boyfriend of 6 months was over him refusing to read Harry Potter because it was (and I quote)"C-R-A-P!"
-when you don't talk to your boyfriend for two whole weeks for the above reason. Yeah, you don't do that around crazy HP girlfriend and expect her to talk to you...

-When you're at work and a customer asks where you got your Gryffindor necklace, you strike up a whole HP related conversation with them.

-When you wear your Gryffindor or DA necklace to work just for the sole purpose of hoping that customers will notice it and strike up HP conversations with you.

-When someone asks you if your Gryffindor necklace is your family crest you think, 'I wish', but you're very happy because your real family crest does have Gryffindor lions on them.

-When you write more fan fic than original fic.

-When someone says they don't like HP, but they've only watched the movies and never read the books, you want to scream.

-When you and your siblings regularly pretend to be various HP characters.