You know you are a nerd when...

...you're reading a vampire book and your brain decides to craft an evolutionary explanation for why a vampire might have an aphrodisiacal bite.

When... You spend 3 hours trying to invent anti-gravity (and the ensuing flying cars) and honestly believe you're making progress.

You see the name "Jon Snow" trending on Twitter in the UK and you immediately think "GRRM's A Game of Thrones", not "famous Channel 4 newsreader"

(Happened to me today...)

...your idea of a great night is sitting with your husband reading a book while he sorts pennies. And that book is a biography on King Henry VIII.

... you spend an entire long weekend debating the similarities and differences in theme and style between Doctor Who and The Hitch-Hiker's Guide To The Galaxy. With 5 people on the internet.

you have regular, in depth conversations about obscure points in Old Dr Who and theorise what it means for the revival series.

... you can quote Shakespeare from memory but think Eminem is the little chocolate candies from those tv commercials.

...at Oktoberfest, you sit down next to the guy in full mid-19th-century Bavarian military uniform and spend twenty minutes discussing the differences between the Bavarian and Prussian uniforms and organizations.

KyraDune said:

... you can quote Shakespeare from memory but think Eminem is the little chocolate candies from those tv commercials.

Click to expand...

Ah, you've met me, then?

That you don't just belong to a band's fan club board, but also to a separate, secret board for fans of one particular album.

You can recite the Green Lantern Oath from memory.

...when the Intel Inside jingle is your cell phone's ringtone.

...when your instant response to any Labyrinth reference is to immediately start rattling off the lyrics to Magic Dance, correctly.

Cliff Face said:

... you spend an entire long weekend debating the similarities and differences in theme and style between Doctor Who and The Hitch-Hiker's Guide To The Galaxy. With 5 people on the internet.

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. . . you see this post on an internet forum for writers and feel obligated to pitch in by saying that Douglas Adams was a significant writer in multiple early episodes of the first Doctor Who.

Alternatively, you write songs about Pride and Prejudice and raps of Marxist writings in your spare time.

Aidan Watson-Morris said:

. . . you see this post on an internet forum for writers and feel obligated to pitch in by saying that Douglas Adams was a significant writer in multiple early episodes of the first Doctor Who.

Alternatively, you write songs about Pride and Prejudice and raps of Marxist writings in your spare time.

Click to expand...

"We have a winner!"

when you rewire the power running through the kitchen's crawl space three times to get it all placed just right.

You start a thread about being a nerd.

For me? Personally? I know I'm a nerd when I wake up in the morning and see my reflection.

Not geek. Nerd. 100%

...you build your own computers specifically to meet the specs to play certain video games.

. . . you run into another tarantula hobbyist and start an animated conversation full of Latin names, acronyms, and slang nobody else understands.

Your ring tone is the theme from Close Encounters, and your text-message alert is the sound a Star-Trek communicator makes. (OK I am not enough of a nerd to know the proper term for this noise, but I bet there is one).
And you know your friends are nerds too when you can have conversations almost entirely composed of quotes from Aliens, Terry Pratchett and The Thirteenth Warrior.

...you get a pet rat just because you needed a topic for a science experiment.

~Amber~

...you not only have an entire floor-to-ceiling bookcase devoted to works by Neil Gaiman, you've got another one full of Stephen King stuff as well. In your bedroom. So nobody touches them.