The mind wants to run and the discipline grabs the wheel, correcting you before the thought is even finished. Mercury squares Saturn, the quick thought catching against the slow structure. Speed up and you flog yourself for imprecision. Measure too hard and the spark of the idea goes out. You paid in long stretches of block where you thought so much you wrote nothing, and other stretches where you did write but the page embarrassed you. What you ground out was the habit of shipping drafts. Only the disciplined eye, passing over the rough first try, makes good prose. The discipline you carry is one of process, not of the instant finished thing.