I've had a similar situation with Kotlin. I've always been a java developer, and I enjoy using it, but even with the newer features it's just...slow.
When I had to script things I chose JavaScript (native JavaScript) since it's way faster to iterate, but I've always missed the static typing (I also know python, but I honestly prefer JavaScript)
Until I learned Kotlin. It's been a blast to use, incredible common libraries, streams everywhere, nulls that you can use without issues...I just love it (so much in fact that I'm in the process of switching project from java to Kotlin).
When I need to do scripts, like for the advent-of-code, I choose Kotlin.
I also really enjoyed the jump into Kotlin as well! That said, I'm also very happy with recent java versions trying very hard to close the gap. It does feel like at least half of Java's recent major lifts have been to emulate things done well in other languages (a great attribute for a self-aware language developer). I definitely never appreciated a lot of their newer feature choises like records until I saw them working really well in Kotlin data classes.
When I had to script things I chose JavaScript (native JavaScript) since it's way faster to iterate, but I've always missed the static typing (I also know python, but I honestly prefer JavaScript)
Until I learned Kotlin. It's been a blast to use, incredible common libraries, streams everywhere, nulls that you can use without issues...I just love it (so much in fact that I'm in the process of switching project from java to Kotlin).
When I need to do scripts, like for the advent-of-code, I choose Kotlin.