If you've never learnt a language that works with cases, you'll find everything mind blowing. The fact that a name like "Mark" can change when I say "I talk with Markon", "I see Marka" or "I give Marku a book" can make your brain melt down.

My best piece of advice is to practice speaking as often as possible so cases go naturally out of your mouth. But be careful if you don't learn them properly the first time you won't get them right never ever.