A few years back, I was at the trainstation, waiting for my train to arrive, and I overheard a conversation between a few teenagers. Two of them were caucasian, one of them had a bit darker skin. One of them asks the darker one where he is originally from, and he replies that he's from Egypt. So they ask him if he speaks whatever language they speak in Egypt. He does. He proves it by saying a few words in arabic. Just a random sentence that pops up in his head. It was something about the weather, if I recall correctly. The other two are impressed. They only speak dutch, english, a bit of german and a bit of french, so they can't understand a word of what he was saying.

They want to hear more.
They want to know how to ask someone's name.
They want to know how to tell a girl she's pretty.
They want to know how to tell a guy he's an asshole.
They want to know how to tell someone to fuck off.

I used to think that such a thing was typical for teens who want to be cool by telling their enemies to fuck off in a language that they can't understand.

For two months now, I've been working at a company where almost 25% of the people working here is from the USA. The most common languages you hear here are dutch and english, and all the yanks (that's what they are called around here) are a bit amazed at how we Dutch people have no problem switching between english and dutch.
Last few days, I had an American visitor here, a guy, about fifty years old, who would show me a few things. He told me a funny story.
He was on the airplane to Brussels and he sat next to a Dutch woman. They talked a bit and he asked her how to say what his name was in dutch, and how to ask for someone's name. The woman learned him a few dutch sentences. "Pokkeweer" was one of the terms she told him he had to remember, because it's always bad weather here (that's what it means).

One thing he heard the woman occasionally say, and he asked me what it meant, was godverdomme. I started lauging, so he became more curious as to what it meant. It means goddamn. For the next few days, everytime something went wrong, he was saying godverdomme. And only then I noticed that most Americans here curse in dutch when something goes wrong. I hardly ever hear a damn or a shit or a fuck from one of them. It's always godverdomme or kut when one of them curses. Ironically, when one of the Dutch guys curses, it's usually fuck or shit.

So, what I first thought, about teens who want to be cool, was wrong. People of every age do it.
Why? I have no idea. It appears to me that there's something special about knowing how to curse or call names in foreign languages.