Hm, obviously I don’t know why people downvoted, but one guess: “german” is historically someone who speaks the German language (as their mother to gue), and contemporarily someone who holds the German citizenship. So if neither of those applies to you, but call yourself German, one might assume that you subscribe to the view that there is a German “race” which you consider yourself a part of, which is not a popular view.

Get a drink with more alcohol in it. It will survive longer