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.