It's interesting: shop at Morrison's, Asda and Aldi and people get in your way because they are too thick to notice; shop at M&S and Waitrose and people get in your way because they are too up their own behinds to notice.
.... and in Tesco they can knock you down because they are too busy running around looking for offers and in Sainsbury it's like doing a slalom as the OAPS are riveted to the spot.