You know you're German when ...

You call your cell phone "handy" and a projector "beamer".

Your childhood diet consisted of Alete and Zwieback. Your college diet consisted of Miracoli and Döner.
You grew up watching "Löwenzahn" and "Die Sendung mit der Maus". 
You have ended an English sentence with "..., or?".
You expect chocolate in your shoes on December 6th.

You are obsessed about protecting your private data... but answer the phone with your last name.
You are at a crossing and there is not a car in sight. You wait for the light to turn green before crossing.

you know that Sunday shopping is something very unusual (and even that only in larger cities), so you plan ahead

you’ve taken so many train trips in Germany and Europe, you lost count long ago (“Senk ju vor träwelling”)

you are almost fast enough at bagging your own groceries to beat the supermarket checker before the next person in line starts to push you out.