Fairly soon after I started running, I ran in a 5k and recorded a decent time for a guy my age. Yesterday I came up with a chord progression of some sophistication, but I realized I was using similar ideas shortly after I started writing songs in the first place. Once I started doing these things, I was simply doing them and haven't necessarily improved much since. So, too, with meditation: I probably won't be all that much "better" at it in five years than I am now. That's ok, though. Establishing the habit is the thing, not necessarily improving it every year.
There are improvements too. For example, I can now play piano a bit better, even if my songs are basically of the same quality. I'll take those, but I think the main thing is just doing it in the first place.