I'm assured that the more I attend to my painting, the more neural pathways I am creating in my "paint centre". It's not just experience. I am actually improving the wiring in my brain. "Our brain is marked by the life we lead and retains the footprints of the experience we have had and the behaviours we have engaged in," The Mind and the Brain, p212, by JM Schwarz and S Begley.
My genes are the canvas. The strokes I make reflect my personality (bold, colourful and full of light). And hopefully both the strokes I make and don't make, are also the result of learning.
How do I know when a painting is finished? Experience. Good teaching inputs.
Why do I see that section as purple when another painting might see blue? Genes. And experience.
The ultimate irony is my ability to see both the beauty of a masterful painting and the awful gap that yawns in assessing my own work. The greatest learning of all is to let go of judgement while a brush is in my hand.
Before when planning, yes. After when reviewing, essential. But never while working. My brain is deep in paint.