it's interesting that mental self-editing can be considered a "weak point." it sounds like he's really doing 2 (fabulous) things at once there - he's clearly on-task, brainstorming his ideas, and then on top of that, he's honing/selecting the ideas to produce quality work. frankly, that is a much more advanced process than simply writing down the first thing that comes to mind. so regardless of any other possible issues... i think major congratulations are in order! (at least from me!)

Every Sunday it brooded and lay on the floor. Inconveniently close to the drawing-room door.