Will I have difficulties with customs in Europe?

I'm travelling to Germany this December and will stay there for travels and an internship. I'm taking 4 pieces of luggages and taking many personal belongings including brand items glasses, hats, belts, camera, wallets from Gucci, LV, Nikon, Ferragamo, Boss and so on… Also my iPhone5, an iPad and my ipod. It's all used and my personal belongings. There are no receipts or duplicate items nor any originally packed things… But I got worried because my friend from Germany told me I need to be careful with customs because they might think its commercial goods or I'm trying to smuggle things and charge me taxes… I was like WHAT? Charge me for my things? He told me to distribute the items in my luggages. Is that true though? I always thought that if I take many things that are originally packed I'll have to declare them, but not my personal items right?

Does anyone have personal experiences with this?

If they suspect that you might be bringing them to sell or as gifts, taxes could be assessed. That seems like an excessive amount of luggage for a visit. Customs may well agree with me. I'd suggest leaving a lot of that stuff at home. You aren't going to impress many people with all those fancy brand names.