Here’s where some of the confusion comes from: The EU has a passport control when you leave the EU, and there I show my EU passport. I haven’t ever seen a similar passport control when leaving the US. When I check in for my flight from the EU to the US I use my US passport. When I check in for my flight from the US to the EU I use my EU passport.

Have been doing this for years and haven’t had a problem.

Sweden. I immigrated from the US in my late middle age. I felt my expertise and teaching abilities were much more respected and appreciated than they were in the US.

We split our time between the US and Sweden. My wife has dual SIMs in her iPhone and is fairly content with it. I got frustrated with the fact that your AppleID is linked to a particular country’s App Store and credit card, which means there are apps I can’t access from the other country (without signing out and having to go through the hassle of logging in/reauthorizing lots of apps). I finally ended up with two iPhones and two separate AppleIDs.

In particular it is financial and government institutions that may not have apps on each others’ regional App Stores so your experience may differ.

You didn’t mention language but that was a key factor when I moved to Sweden. Even though almost everyone speaks English you’re not going to get close to them without speaking their language.

Language doesn’t guarantee you’ll make friends though. I got in the habit of always buying an extra ticket whenever there was a sporting or cultural event I wanted to see. That forced me to ask someone to come with me, usually a coworker or neighbor. The great thing about attending an event together is that it takes the pressure off of making small talk and it gives you a topic of conversation when next you meet.

Patience is important. It may take a number of times before someone starts to feel like a friend. It’s ok to work on having several good acquaintances at the same time.

Another strategy that works for some people is join clubs and groups with similar interests.

Best of luck to you. Here’s hoping your social circle grows and prospers.