> But once you put that much actual effort into getting good at it, you stay good
I had the same experience, but I don't think it's a matter of being "good" at the game so much as having memorized all of the stupid ways to die (many of them insta-deaths ) plus how to avoid them, and knowing the mechanics of how to win (I think you're supposed to figure out the invocation ritual by giving tons of money to the Oracle, but it's been decades and I can't recall if I learned it that way or just read spoilers). edit: just remembered the whole vibrating square thing and that there are a few ways of making a run unwinnable, which is a kick in the teeth when you have a promising @ going.
Maybe that's just splitting hairs (is that just becoming "good"?) but in retrospect, I don't think that getting good at nethack was worth the investment in time and frustration. I will say that playing nethack improved my vocabulary.