Almost every country in the world has a sense of national pride. However, some display it a little more loudly than others. There is a thin line between patriotism and arrogant exceptionalism, and nowhere tramples over that more loudly and proudly than the United States.
Being a world power means that everybody is more likely to listen to you than like, Lichtenstein, but that doesn't necessarily mean that you have anything worthwhile to say. While citizens of any country in the world may have their moments, when it comes to excessive self-confidence it is the land of the free that frequently hogs the microphone.
This is not to say that all Americans are entitled, but certain corners of the internet can make it difficult to feel any other way. So long as the attitude of the examples below is avoided, we can all do our best to get along just fine.