Why It's a Good Idea to Learn a Second Language
I probably shouldn't be telling people to learn another language. I've been a writer and an English tutor for years, but somehow those skills haven't transferred into studying other languages. I've had a longtime slugfest with German grammar, and I'll probably be proficient in Russian by the next Ice Age.
But don't go by me--learning another language is a great idea. Just the mental challenge of it is beneficial. Acquiring foreign language skills requires serious study and lots of memorization, no matter what some commercials may say. You know the ones I mean. It requires using logic to figure out meanings from root words. And, ironically, you'll have to leave logic behind as you master a language's grammar, which is often arbitrary.
All this will make you much more understanding of people who are learning English, and you'll run into them almost everywhere you go. If you work in education and come in contact with English as a Second Language students, studying another language yourself can be invaluable, even if it's not the language all your students speak. Just understanding the process of acquiring another language can help you help them.
Learning another language brings you in contact with the culture or cultures that speak it, and gives you more familiarity with them. Language and culture are very much intertwined. For example, in Wales the Welsh language has been revived and people there speak both English and Welsh; signs are in both English and Welsh. It was important to the Welsh to preserve their culture and to do that they had to preserve the Welsh language. In Ireland Gaelic has been taught in schools for many years, for the same reason.
Once you learn a language, it's often easier to learn related languages. People definitely find this is true with Romance languages. I know a lawyer who minored in Spanish and now works with documents in Portuguese. Depending on how closely related languages are, it can be quite easy to figure out a new one from one you already know.
If you're a big reader, and most people who are interested in languages are, you can read the best writers in their own language. Imagine reading the words Cervantes, Victor Hugo, Goethe or Dostoevsky actually wrote. How exciting would that be?
Knowing another language will certainly give you a sense of accomplishment. That may very well translate (no pun intended) into self-confidence. You've tackled a really big subject, stuck with it, and mastered it.
Come to think of it, I'd better get out those Russian books!