Yes, and unless you're planning on an extended stay somewhere you'll put it to use, there are so many alternatives which are likely to be more valuable than learning a language.
There are other reasons to learn a language, such as access to its literature. For example, once I left school I was no longer in an "extended stay where I could put it to use" (in this case, Greek and Latin) but the pleasures of the languages and cultures (especially the ancient Greeks who were _weird_) caused me to continue to use them.
But learning _anything_ is good for the soul...and as Blake said, there is a universe in a grain of sand.
"Learning and practicing something, for instance a second language, strengthens the brain"
So it is not just languages, but generally learning stuff. Who would have thought...