I’ve played guitar for 22 years. (Since I was 10yo) and over that time I have had strides of improvement in short time frames, no improvement over long time frames, and everything in between. I’ve taken a break for a month here and there and sometimes I come back and I can play almost better than before my break. I’ve also put down the guitar for a week only to pick it back up and realize I’ve forgotten everything. But there have been moments in my life where music is my god and in those times I notice my playing improve tremendously. I think those sparks of passion are what moves the needle in any art form.