Finish the sentence :3
and/or a yeti by the Yeti!
your friends start to qualify your Harry Potter merchandise as a 'collection'.
You know that you're a nerdfighter when...
You walk up the aisle to the theme from Legend of Zelda (yes I really did, and the organist played it beautifully)
You make an Android app just to keep track of all the kinds of stitches you need to remember for your craft project
Plan your time carefully so you can finish Skyrim before Skyward Sword comes out =^_^=
you are sitting in a movie theater and you see a trailer for Journey 2 and you yell out "OMG! ITS A PUPPY SIZED ELEPHANT! IS THIS ISLAND NERDFIGHTERIA?"
Your friends write DFTBA in your Christmas card.
...you're at a Christmas party talking about Giraffe sex and honey badgers.
You meet someone truly awesome and think, "He/she would make an awesome nerdfighter".