@Judeau From my own experience: You don't just have to memorize the meaning, but also the pronounciation. The fun stops when you read a new word somewhere, and then don't know how to pronounciate it.
I guess every language has its hardness. In German, you'll have the pain of splitting endless compound words at the right places to get their meaning, and breaking your tongue when trying to say them.
@nwehrle I really like German in a sort of love/hate way. I studied it for 5 years in primary and secondary school, and I understand quite a lot when I read it or listen to "formal" (polished) speech, but whenever I try to express myself I just get ethereal lists of prepositions in my mind, and I probably sound like a boxer who has been hit on the head one too many times, stuttering and mumbling...