Ahhh, the good old realization. It took me quite some time as well to understand that. I also go through cycles with artsometimes it's art block, sometimes it's indeed doodling, sometimes it's a sudden breakthrough that allows me to draw right something I couldn't really draw before. Which doesn't mean my art suddenly becomes TheAwesome!, but if one element is improved, I'll take that any time over no improvement at all. (Not that my art is very realistic, anyway. Oh well.)
I wonder if we're actually meant to find a set point in art. Maybe we can simply go on evolving until our dying day, or something like that.