lol, fantastic catch :-D

For every one not familar with german laws: You must drive right unless you are overtaking a slower car that is in front of you. And you are only allowed to overtake on the left side of another car. So if everyone drives the left lane, there's no way of overtaking anybody - something that would drive (no pun intended) all the other drivers nuts and you start to honk like crazy (which you are not allowed actually) or to give signals with the lights (which you are also not allowed) to the car in front of you ;)