I've lived (stayed for more than a year) in six different countries. The longest I've lived in one country was the US, 16 years. I moved there as an adult already. Since then, I've been living in Ireland for the past 15 years.
I view countries like products. I move to the one that suits me best at the moment. I work, pay taxes, volunteer and otherwise contribute to society as a payment for the privilege to stay, and I live fairly comfortably, based on my stage of life. The US, for example, was great for higher education and saving up money. Ireland sucks for the young and old, but is perfect for the midfle aged middle class. Once I retire, I'll look somewhere else again.
Applies to airport security checks as well.