Double Dutch

In a cast in Skypeland about Democratic Systems, one man from Holland came in to complain that Americans did not understand what the phrase "double dutch" meant. Apparently, in the UK, "double dutch" is a colloquial expression meaning a language that is difficult to understand, but in the US it means a game of jump rope:
http://www.answers.com/topic/what-is-double-dutch
http://www.answers.com/double+dutch&r=67

I was amazed to hear the narrow mindedness and witness the basic ignorance and the inability of these conceited Skypeland visitors to use standard internet tools or dictionaries to look this phrase up. These characters preened and patted themselves on the back for knowing this phrase which an American supposedly did not know.

I guess they do not understand that English is a huge language, with literally millions of words and many many regionalisms. For example, English is adding 10,000 to 25,000 words a year, and by one estimate has about 1 million words:
http://www.npr.org/templates/story/story.php?storyID=5182871
or if you include technical words, well over 10 million words (the Oxford Dictionary has over 600,000 words in it). There are about 1.6 billion speakers of English in the world.

By comparison, Dutch is much smaller. It has 350,000 words in it, and only about 30 million speakers:
http://en.wikipedia.org/wiki/Dutch_language#Vocabulary