I have often thought of walking as moving diagonally as opposed to linearly. In a car, you are forced by the grid of roads to move in straight directions. You are forced also to see only the fronts of things, the one and only flat side of three dimensional objects which is meant to be seen. But, while walking (or riding a bike, if you dare to get off the pavement), you can move diagonally across the created grid. You see the back side, the flip side, the wrong side of things. You learn the secrets that are hidden by their facades.