Every man is wise when attacked by a mad dog; fewer when pursued by a mad woman; only the wisest survive when attacked by a mad notion.
At first, I see pictures of a story in my mind. Then creating the story comes from asking questions of myself. I guess you might call it the 'what if - what then' approach to writing and illustration.
The human young must learn to perceive these affordances, in some degree at least, but the young of some animals do not have time to learn the ones that are crucial for survival.

