European granularity
6 years living in Europe and the only thing I didn't get used to yet is the granularity of everything. If I drive for 2h, I'm in Spain, and then if I go for more 8h, I'm in France. All fine and good, and different languages aren't an issue.
Services, on the other hand, can vary so much that I get lost just by thinking about them.
What I use to pay tolls in Portugal doesn't work in other countries. The banking app to instantly transfer money doesn't work in other countries. If I want to sell something on the internet, it doesn't calculate shipping on its own, I have to manually input information on each of the shipping companies that exist and serve different countries. If I want to buy something, I have to check if the website sends it to Portugal. A lot of companies have "local" websites with broken links or broken systems, and if you access the central one, it won't have information about other countries.
There's no unified place to find information about this stuff, so you kinda have to know where to look and dig a bit and pray you found a reliable source. Just recently I discovered that I can't drive my car in Madrid, for example. Not that I want to go to Madrid, but if I were to drive through it without knowing about this, there would be a hefty fine.
At least roaming is at local cost everywhere, so there's that, because I don't know what I would do if I had to buy a new sim every time I drove for more than 3 hours.
It's the biggest contrast I have with Brazil, regarding day-to-day life. It's kinda mindblowing, to be honest.