I agree with Keiichi. I'm just beginning but I'm already having headaches over vocabulary. It's not that it's difficult or different from other languages... it's just that you have to learn N thousand words over again. A new symbol to go with the concept. And you can't cheat like in other Western languages because the words are similar to English. (Assuming foreign loan words are the same as they are English is dangerous ;) ). Keiichi is lucky that he has a structured class, though. I have a few dictionaries, Japanese For Dummies, and a couple of websites. And I have to improvise from there.

Learning the kanji is definitely the second hardest part for me. Writing them is simple enough once you learn the stroke rules. Learning their meanings is a prodigious feat of memorization - pounding it into your head with repetition so that by the time you know it you've forgotten yesterday's batch. I'd say my personal biggest problem is the fact that right now they all look EXACTLY THE SAME. Well that's not quite true. It just looks like there are only about ten kanji, and they're drawn sloppily. My eyes just glaze over; my brain treats it as pictorial information, not language information. Well technically it *is* pictorial information but it should be processed as word-symbols. My brain just looks at all the pretty pictures.