I do a lot and mainly Spanish and German songs. Not understanding the language makes me focus more on the melody and the performance of the artist. But I do usually search for the lyrics' meanings (or just the lyrics) when I get obsessed with the song.
Tho a lot of times I memorize a song entirely by sound without understanding a single word (usually I'd be pronouncing everything wrong, but who cares as long as I'm singing along

)
Edit:
Here's an example, from an album I memorized entirely and still don't know that's which language: