You know you're a nerd when............... a woman asks you out for a Friday night movie, but instead you suggest that the two of you spend Friday night at the local library yelling "WILL YOU PLEASE BE QUIET" to all the other nerds that are turning the pages of their books too loudly!!!
Needless to say, she did not take me up on my offer, and I had to yell at those nerds by myself!!!
On a related note: you know you're a nerd when.................. you get viciously beat up by a gang of book-worms at the local library for yelling obnoxiously at them all night!!!
I still have the pen-protector scars on my face from that night.