Being European, I find what you've just said very closed minded. I've spent time in many parts of Europe and and also in your country. You can be proud of your country, that's fine (although one thing that does gripe us brits who know your history, is that you think you are different from us. You ARE us. War of independence... it was essentially Brits against Brits, we never gave Americans independence, we gave our own people independence. /Rant) but to say that your people are more friendly than the rest of the world is really quite offensive to the rest of the world.
I have come across many childish Americans, the issue I came across on this very forum was not dealt with well and a part of that came down to the fact that I was being told I didn't know anything about you both when in actual fact you didn't know the first thing about me. That's not exactly admirable behaviour.
Europeans can be feisty, they can be just as childish as other people (including Americans), but they can also be just as lovely as anyone else. They are entitled to be proud about what they want also. And from my experience some of your issues probably come from over reactions and miss understandings on both parts.
When on an international forum you have to remember that people from different countries/continents are from different worlds pretty much. Some things just have to be taken with a pinch of salt and not retaliated against.
Just my tuppence.