Ponce, Puerto Rico

On the lighter side of things: Just returned from vacationing in Ponce, Puerto Rico. I attended a friend's wedding, held at Castillo Serrallés. This picture is taken from the hill on which the castle sits (castle is just to the right of frame), overlooking Ponce:

Hundreds of years ago, this hill was used for monitoring Ponce's Caribbean harbor. Today, the overlook is the site of iconic Catholic imagery:

Like many areas with colonial Spanish influence, the spoken language is Spanish, even though Puerto Rico is a US territory, its currency is US dollars, and there are no customs when flying to/from the United States. That led me to wonder idly, what would be a good set of languages for a "person of the world" to learn these days?

Looking a this chart, I can see that I'm already ahead of the game with English (the international language of business), a smattering of Spanish, and a tiny bit of Mandarin. I also tend to think that your average multi-lingual person can only command a good conversational grasp of five to six languages, and a good written grasp of 3-4 languages.

So, the list I came up with, for myself: English, Spanish, French, Mandarin (and written) Chinese. That covers huge swaths of each continent. I discounted Hindi because English is often known in areas that speak Hindi. I remain unsure whether I should add Arabic to my personal list of languages. Chinese will take a long time to master, and lumping Arabic on top of that is a lofty goal. It seems like learning right-to-left reading would scramble my brain, too...