Just for the record this is an updatet version. The original is deleted.

…you read in a crossword "Brave man in the Roman Army" and think the solution is Rory.
…every time you see someone with a bow tie you think "Bow ties are cool".
…you have tried Fish fingers & Custard.
…you have seen that one picture of David Tennant, where he is naked.
…you have been to a gym,saw David Tennant and asked him after an autograph while he was under the shower and naked. (That really happened to him).
…you want a TARDIS so you can travel back in time and can watch the lost episodes.
…you are angry with someone and shout exterminate at them.
…someone says Florence Nightingale and all you understand is Lawrence Nightingale, a character from Blink.
...you own a life-size K-9,Dalek, TARDIS or something else.
...you have been to the Doctor Who Exhibition in Cardiff or the Doctor Who Experience in London.
...you have been to The Who Shop in London.
...you use the word TARDIS as an adjective.
...someone says doctor you think Doctor Who?
...you think that portable toilet is in real a TARDIS.
...you look in the sky and wait to see a TARDIS.
...you annoy your friends with Doctor Who facts, even if they aren't interested in the show.
...you smile when someone in TV mentions Doctor Who.
...every time you watch television and see someone from Doctor Who you scream:"Oh my Godm that guy played in Doctor Who".
...you watch movies,you normally wouldn't watch just because someone from Doctor Who is in it.
...you use words like Fantastic,Allons-y,Molto Bene and Geronimo a lot.
...you don't say yes, you say affirmative in K-9 voice.
...you see the statue of an angel and think "Don,t blink".
...you are scared of people with gas masks, people with straws, scarecrows and of course Statue of Angels.
...you don't eat pears anymore, because the Doctor hates them.
...you use a screwdriver, you make the sonic screwdriver noise.
...you don't go at christmas out of the house, because you think there will be an alien invasion.
...you own a t-shirt, which says "The Angels have the Phonebox".
...you own a long Tom Baker-Scarf.
...you own a jumper with question marks, like the seventh Doctor.
...you have had a discussion with your teacher who is the best doctor.(That is the truth and it is a wonder, as Doctor Who isn't really popular in Germany)
...you had to do an essay and you did it on Doctor Who and got an A. (It is good when your English Teacher is a Fan aswell)
...you see a sink plunger and ask yourself what happened to the Dalek.
...you read in a magazine that plaid shirts are "in" in Britain and you think that is only because of Amy and Rory.
...you are scared of the crack in your wall.
...you know how to dance the Drunk Giraffe.
...you see a picture of Rene Auberjonois as Odo in Deep Space Nine, and think that this guy looks like The Flesh.
...you watch the movie "The Kings Speech" and start to smile as you hear that one guy has the nickname "Doctor".
...you think that Quentin Tarantino looks a bit like Ianto Jones.

Also thanks to for these
...you can identify Cybermen by Doctor era
...you can name the two TARDIS's with the St. Peters emblem
...you have watched all 780+ episodes
...you have read novels, comics, and listened to audio dramas
...you can name all the Doctor's actors, plus the non-canonical ones...
...you can name all of the Doctor's companionsIn order.

EDIT
Thanks to for these:
... you jump everytime someone says:silence"
...Bad Wolf
...you always take a banana to a party
...the mention of the number 10 makes you swoon uncontrollably
...Run!
...having two shadows is a death sentence to you
...you know what raxacoricofallapatorious means.
... You claim your refrigerator is a TARDIS with a broken Chameleon Circuit.
...You search the town for blue police boxes.
...You suspect that Barty Crouch Jr. in Harry Potter and the Goblet of Fire is the Doctor undercover to fight the alien Voldemort.
...You search through history books for some mention of a doctor with a blue box.
...When you become bored, you spend your time by constructing a TARDIS out of Lego pieces.
...You stare at anyone who is drumming their fingers on a table with a beat of four.
...Someone makes the emoticon '-_________-' and you scream "FACE OF BOE!"
...Your favourite fruit is a banana.
...You say 'Team Dalek' in response to 'Team Edward or Jacob?' questions
...You named a trampoline Cassandra.




Do you know any more?
Write them down in the commentary section.