There's a new girl in my office, and she...drum roll...speaks Welsh! I haven't had anyone to speak to in years, and it is very gratifying to be able to call out a Bore da! Croeso! and have someone call back Diolch yn fawr! There's a funny thrill that goes through you when a) someone understands you, and b) you get to put into use something you've been hauling around with you for decades. It's like carrying around a key in your pocket and finally locating the lock it fits into. All that work to learn the language in the first place finally justifies itself with a greeting.
I suppose it's an apt simile. Language can unlock doors, after all. Entire vistas opened in my mind when I started learning Biblical Hebrew. Suddenly the things I'd read since childhood took on new and intriguing meanings. (Just as a quick example, the word for a long loose-sleeved robe leading to the idea that angels have wings.)
When you can draw parallels between words in different languages, you have a new avenue for entertainment and humour, too. Words are fun to play with. Like handschu for "glove" in German (literally "hand shoe"). Or you can mix up the "Shma Yisroel" with Welsh "sut mae" (pronounced almost the same), and suddenly instead of the great call to the nation, you have "How ya doin', Israel?!"
My husband was once waiting in line at a government office, and the elderly man in front of him was having difficulty making himself understood. My husband stepped forward and offered to translate. In a few moments the man was happily on his way. I asked my husband what language that had been, and he replied, "Hungarian."
I blinked at him. "You don't speak Hungarian."
"No, but I knew what he needed -- he was in the same line I was in, after all -- so I just helped things along." So there you go. No words even needed.
I have studied a lot of languages over the years to varying extents and for different reasons. Some were entirely to meet school requirements, others out of interest, and Welsh I started so I could do geneaology. All have made my brain an entertaining place for me to hang out in (there's another fun thing for you--stringing prepositions together willy-nilly) even if they haven't been overly practical. My children all started off in French immersion school, and even though they haven't gone very far with the language, I do believe it has enriched their experience so far. If nothing else, it has taught them awareness of other people and cultures.
I kid you not, someone once came up to me and asked if I spoke Spanish, and when I answered, "Welsh, actually," he honestly replied, "Close enough. They're both foreign!"