Oh, the joys of being a multi-linguist!

I am sure most Indians who have gone through high school are well versed in at least three languages - English, a regional language and Hindi - the national language. In case of people residing outside their native state, one could add the mother tongue to this list as well. When I say well versed I mean speak, read and write in at least one and at least speak or read in the other two.
I have mentioned that I speak English, Hindi, Marathi and my mother tongue in Malayalam for good measure in this post. I am sure there are many such stories out there.
What are the not so obvious advantages of multi-linguism?
On the lighter side, I would say would be that I can watch a Bollywood masala movie and experience the typical euphoria that a good flick does without caring much for a true depiction of real life. However if I would like to watch a cold calculated, well researched and realistic movie that has a storyline worthy of a novel, I would go watch a Hollywood blockbuster. And I would undergo a totally different set of emotions for either one. It would be like a switch turning off on one set of perceptions and turning on another.
I am sure a monolingual person can never in his life experience that.
A more useful result would be one where a person would be wearing a different thinking hat each time he converses, reads or writes in a different language.
When one converses in English, he would tend to be formal, business like and professional - the language of the work culture. In a regional language one would switch to a more rustic ambience and try to share the bond of the local language. In Hindi one would be speaking the lingua franca that binds all of us together as the most understood language pan-nation. In one's mother tongue, like how this video parodies, he would be striking a bond that relates to nativity, a bond among Indians that binds better than any other. Not only this, when one speak in any of these languages, he would actually become part of that culture, transforming himself for that moment to a representative of that culture.
Any more ideas out there?