You don’t really know nationalism until you’ve lived in a foreign country. People back home often don’t accept/trust things you did in the other country, sometimes even things you did at an embassy, and vice versa. Government officials in the home country ask you questions like, “why would you want to live there?”, and require you to help them spy on you and tax you (e.g., tell them what foreign bank accounts you have). People at foreign company and government offices usually ignore your emails. And locals of the other country often treat you suspiciously. People in other countries are usually nice to paying tourists, but not so nice if you try to live there.
Similarly, you don’t really know culturism and racism until you’ve lived in an area where you are in a cultural or ethnic minority. People constantly stare when you walk down the street, and sometimes comment on how (dis)similar you look to them. Taxis and buses don’t stop maybe half the time, and people are physically pushier with foreigners on buses and in crowds. Customer service people in businesses avoid you unless you confront them, and local customers cut in line ahead of you. It’s harder to get a job and to navigate relationships of all kinds. People often don’t want to hear or see things from your culture. People from both cultures sometimes do mocking/poor impressions of the other culture or ethnicity in front of you, and expect you to find it funny. And people are judgmental and rejecting, if you look or speak in any way that they don’t find beautiful/healthy, humble, thankful, and positive.
In such an interconnected world, it’s amazing to me that many people are still so small-minded.