I've been learning German too myself, and the thing that the traditional language courses don't teach you is the way natives speak. Listening to actual German speakers was pretty much alien to me even after two years until I bumped into a couple Easy German videos where they touch the very same subject as this xkcd and that actually got me listening to certain parts of speech more carefully and that way also understand it better.

Now I actually find myself doing the same shortcuts sometimes when I'm progressing with the skill. It's the same with English since I have to use it daily at work even though I'm not a native speaker. Funny how the languages work in real life vs. in theory.