Well, I grew up speaking Dutch. Back then, in Holland, everyone learned French, German and English in high school. I decided that adding Spanish was a good idea and then when we traveled to Italy so much I learned quite a bit of Italian. I agree languages are fascinating and great mental exercise.
I was always told that you could safely say that you mastered a language if you dream in it, and I dream in English!

The Dutch are amazing linguists! I'm always so impressed with Dutch travelers, they adjust so well to different languages and cultures. I have several Dutch friends here and they all speak at least 3 and some of them 5 languages. One of them is busy taking classes in Maya right now. We were in the market one day and she spoke Maya to one of the vendors, it knocked her socks off! She couldn't believe this blond was speaking to her in Maya. She told her she had a good accent and was very understandable.

I think that continuing to learn and be interested in new things does really keep your brain working better and keeps you feeling better too.

I've always found languages fascinating and found while I was travelling Europe new languages came to me reasonably easily. I spent 4 years in Europe and kept clear of English speaking areas, if I wanted English then I could go back home. I spent a bit of time learning Chinese but never went right through with it. But I've also been learning some of the Australian Aboriginal languages. That's been a real challenge, the structure of the languages is so different to all others. But it's fun. Language is culture, it's hard to understand a culture without understanding the language that cloaks it.

very well put!