Languages

I was born and grow grew up in Moscow, but i'm not Russian, actually. I'm Azerbaijani. So i'm bilingual, and i'm really proud of it because when u you know more then 1 language from your childhood it's easier to learn other languages. Also i know Turkish, because it's pretty similar with to Azerbaijani, and i just really love Turkey: the language, the culture and the country are just amazing! I've been in to Turkey many times and i still want would still like to go there again.
So why do we have to learn languages?
I think every language is like a person. All languages are different, it's like the other another planet (planet of languages?) and it has its own countries, nationalities, mentalities. (I'm not sure I understand you here. You start by saying a language is like a person. Then you say a language is like a planet... so maybe you need to think about how to explain your idea a little more.)

For example, there is not such a no word in Russian and English like a the Azerbaijani word, "hesret". It's hard to explain, but it's a beautiful one.
Or i really like the Russian word "товарищ" - it means something like "friend" but it's more then friend, not a brother, not a friend, just Товарищ.

There are a lot of such a examples, but the main thing is that it's good to know languages. Even 2, it's still good.