Yes, I wonder when kids develop the "move over" sense. DD is five. We will be walking next to each other at the supermarket, meet another cart in the aisle, and EVERY time I have to tell her to walk behind me or in front of me to not be in the way. When a cart is headed right for her face, she won't get over. I am the type to always move over to let people go through though. It really annoys me when people take up the whole aisle, sidewalk, road, etc.