I bolded all the ones i've done/do
You buy a pair of shoes / trainers specially for playing DDR.
You start taking a change of clothes with you to the arcade. So that you have a fresh T-shirt to wear on your way home instead of being drenched in sweat.
You only stop playing due to onset of cramp in your legs.
You carry on playing despite having cramp in your legs.
When everyone else sings "Boom, Boom". You say "Mighty fine dollar" instead of "I want you in my room"
People think you have a stutter when you talk about the game.
You dress in the exact same outfit like the characters dancing on the screen in the background all the time.
You have at least 10 mats for the Playstation in case one breaks.
You steal the panels from the arcade and try to attach it to the playstation so you don't have to play with the controls or buy / use those crappy mats.
You try to find all DDR on icq just to increase your icq list numbers and then brag about how you know all the DDR people in the world.
The local DDR arcade is now into the bottle water business.
You ask your new boyfriend/girlfriend "Have you ever been mellow"
The local arcade now has a private room with a DDR machine just for you.
You vote for your favorite DDR song on your national top 30 song on the radio.
Your personal ambition is to be a butterfly.
Your way of getting to know people is by dancing with them.
You dance on your hands.
You have ripped 14 pants trying to street dance (playing with hands and feet)
You have, through MAJOR alterations, managed to make your DDR mat at home exactly the same as the one in the arcade... down to the plastic arrow your swiped from your neighbourhood arcade...
You refuse to wake up from your sleep every morning to go to school, because you dream that you have eternal credits in the DDR machine.
You find yourselve banned from your neighborhood arcade for spoiling 7 machines with your extreme dancing style.
People at the arcade start asking you to change their money instead of going to the operators.
You dance on the 2nd side of the machine, while player 1 is playing his own, single player game...
Songs that you used to dislike are good now, since they were featured in DDR...
You start to wear a white hat, one glove and grabbing you crotch a lot.
When seeing an attractive women in high heels, your first thought is 'how can she play in those'.
At the arcade, you have more entourage than Madonna, Britney Spears, and Beyonce all put together.
You see arrows when you close your eyes.
You see arrows regardless of eyes open or closed.
You tap away steps on your fingers regardless of where you are.
You start doing DDR steps, in the middle of nowhere, regardless of where you are
You have important work to do, but load up DDR or Stepmania instead for a "quickie"
You can name any song on any mix, and sing along.
You know what Delight Delight Reduplication and Diet Diet Revolution are.
You had most/all of DDR Extreme on your pc before it even came out.
You can remember the exact date when DDR Extreme came out.
You whistle/hum DDR tunes
You have DDR ringing tones on your mobile.
You play DDR Music while you work on your PC.
You copy DDR Music to play in your car or on your mini/cd player
You have every single DDR game on your consoles
You are in love with one of the DDR background characters, and/or you can name them all.
You download DDR competition videos.
You have AAA'ed a Expert/Heavy song on the arcade machine.
You have mastered all the songs on doubles on any level.
You only play DDR at the arcade, no other game is interesting enough.