It is an ingrained attitude seen through statements like "leaders of the freeworld", "the great american experiment", "the most powerful person in the world (potus)", etc.
Americans have too much pride in a shithole country. There just isnt much justifiable pride to be found in modern america yet the leading party over every part of government maintains this greatest countrt ever bs.
Great, a lot of times this attitude comes from having not been elsewhere but maybe not with you. I cant personally see any great benefit.other than weather and landmarks but that is just down to size and ability to travel negates it.