“Nationalism teaches you take pride in shit you haven’t done and hate people you’ve never met.”

You can probably substitute any us-and-them term for “nationalism”.

I once had a friend who was routinely incorrect in his football predictions tell me that I, who won about 85% of the office pools during my time there, didn't know anything about the sport because my team had never won a Super Bowl. I then informed him that he must know five times less than everyone else in the room, given that he was a Bucs fan and virtually all of our coworkers were Cowboys fans.

We'll talk over the phone periodically about football, and my predictions about his team are usually spot on for the season. When he asks me how I'm so good at predicting what will happen with his team given that I really don't follow them all that closely, I just tell him that the Saints finally won a Super Bowl, and hence my knowledge was greatly enhanced.

more about tribalism. "I share in the glory of every member of my tribe".