Probably if/when the country does things that makes the individual feel bigger or confirmed in the approach. So, if the person is altruistic, a country doing altruistic things makes them feel good and they're more fond of their country. However, if the person is an asshole, a country doing asshole things, etc.

People are proud of groups that do what they want, or let them do what they want. Good or bad.

Something that has helped them grow as a person or in profession. Or atleast something is a part of that nostalgic portion of their memories.

A country is a fence around a piece of land. Odd in a way that people should feel anything about it.