A midrash imagines universal stillness preceding G-d's giving of the Ten Commandments: "No bird chirped, no fowl flew, no ox bellowed....The sea did not stir, no creature uttered a sound. The world was quiet and silent" (Exodus Rabbah 29).
I have worn my kippah at highway truck stops, to concerts, and while camping. I have worn it in the most non-Jewish neighborhoods. And I have rarely thought twice about doing so.
Jews in Europe do not have that luxury.