When we circle a subject we often end up going round and round in circles. When we spiral a subject we end up with a better result. Walking seems to add forward momentum to thinking- stretching a circle out into a spiral. Charles Dickens considered it 'immoral' to write for more hours than he walked. Walking was how he solved the problems which, sitting at a desk, would have just remained in a circle chasing its tail around his head. People have used walking to come up with new solutions for centuries but by adding the image of spiralling a subject as you walk you'll find your abilities to think things up kick started in a useful way.