I think it's normal to be confused, because the terms and history all have different interpretations and meanings.
What is German? What is Jew? What is "country"? And what is nation?
The answer to all those questions changes. Which is one of the reasons why I think it's important to be incredibly suspicious of any person who claims to have the answer, and to be able to state with certainty that this country belongs to Germany or this is the homeland of the Jews.
What are they really trying to accomplish?
Also, I'm super suspicious of anybody who says about any topic "it's always been this way" or "it's just common sense"... because a) they're usually wrong b) that's usually just obscuring a proposition or action they don't want to justify or defend using arguments so they appeal to nature/God/common-sense/natural-rightness instead.