I was stupid enough to read the English translations a few years back. That and having had to sit through 5 years of German as a secondary school language course (I really hated having to do those classes...I mean, I'm never going to go to need it.....) meant I have a roughly goodish idea of what the songs are about...
So know I cant listen to them without laughing a little. especially when you get songs like Mein Teil, Buck Dich, and Rein Raus
