I get an enormous sense of achievement when I clear my fridge without throwing anything away. This not only includes using up food, but also packaging: to the great amusement of my less thrifty other half, I like to use wrappers to use in lieu of greased proof paper when baking cakes. All this has very little to do with environmentalism and more to do with my general love of thrift. I would have been brilliant during the War.
