I don't know about asia, but european languages are related in so many ways, so learning one can help you understand things written in another.
For example: Norwegian, Swedish and Danish are so simular that they usually can understand eachother. Icelandic is not that far away. Dutch to me sounds like a mix between German and English. People from Finland usually learn Swedish in school.
Now, I don't speak either of these languages myself, but from what others have told me French, Italian and Spanish are related so much that you can get by in a pinch knowing one of those in one of the other countries.
Switzerland has German and French as languages. Belgium has Dutch, German and French.
It really is fascinating how some of the languages are related.
To waste some time, have a look at http://en.wikipedia.org/wiki/Indo-European_languages
I have learned English and some German, but if I would learn another language it would be Spanish.