Learning other languages, you discover how to say the same thing in many different ways. In English we say "goodnight". In Russia, people say "ΠoЗДpаΒЛеНИе". In Vietnamese, people say "chúc ngú ngon", which means "have a delicious sleep". When I think about the word "delicious, I think of pizza, chocolate and ice-cream. I don't think about going to sleep. So depending on the language, different phrases will improve your creativity and force you to think about how to say things in a different way.
Studying a new language, you will notice that you have to learn a new sense of humor that comes along with the culture of that language. Sometimes jokes that work in English won't work in French or Japanese. But sometimes things that nobody would laugh at in English work in Vietnamese. I learned this when I performed the stand-up comedy in Vietnam. A lot of my non-Vietnamese speaking friends would ask me to translate the jokes for them, but when I translated it back into English, no one laughed.
When you learn a new language, you have to learn a lot of vocabulary, new grammar, idioms and much more besides. Doing this, you have to learn memory skills. These could be flash cards, using recall methods, or building a memory palace. Whatever tactic you use, it will strengthen your creativity.
Next time you meet someone who speaks several languages, before you think that they have something special going on in their brain, take a step back and think. Maybe they do. But maybe they've got that special thing because they've made the effort to learn several languages. An effort is something we all need.
