When I was in our loft today, looking for something, I sat for a moment, looking at an old oil painting that I started some time back in the early 1970's. It was meant to cover up another failed painting and recycle that canvas. At the time, I threw down a wash of bright yellow and worked a meandering pattern of organic shapes in primary red and blue. I'm not sure why I stopped, as I can remember feeling very "in the moment" and focused while I worked. But with about 2/3 of the canvas covered, I set it aside and never touched it again. It lived in the attic, in boxes, in closets, and then, more recently, in our loft. I stood it up where I could see it now and then, as I still like it, insofar as it goes. I have toyed with finishing it.
This year I have made many similar starts in watercolor. Some are worth working on some more to bring them to completion. Now and then I haul out a small pile of paintings and focus on finishing them. But finishing is when you discover whether you are skilled or lucky. That is when you discover whether a painting will be art or a learning experience. Either result should be worth the effort. But I always have to ratchet up my courage and draw deep. I almost never finish a painting in one sitting. I need to live with it for a while to imagine what finishing touches will turn it into art.