I here many people at school saying "Oh well, Im German and Italian"
I guess it has partial truth but it holds some lies too.
If you think about it, where you were born is your nationality, therefore you cannot be German and Italian
But, my Grandmother was born in Ukraine and she and her family moved to Germany right after she was born.
According to the above thing where, where you were born is your nationality, my Grandmother would be Ukrainian.
But, we consider her German because she moved there and lived there since she was a baby.
But, if you think about it, does where you were born really mean anything in terms of nationality?
Another good point is people saying "I got my German from the Grandmother on my moms side and I got my Italian from my Grandmother on my dads side."
Well, did they think to put into account that their Grandmother probably said the same thing?
Therefore you would probably have tons of different nationalities.
Unless of course your family has lived in the same country for hundreds of centuries.
But this whole thing also raises the issue of again, saying you are German from your Grandmother because you are basing it off where she was born not what many nationalities she was.
I dont know why the whole thing has been bugging me lately but it has.
TL;DR : Probably too complicated for you too understand anyways.