You buy a bunch of coriander, it's quite a large bunch, and you put it in a cup of water so that it doesn't die. Two days later you notice some slimy bits yuk, you take the bunch apart, washing the slime off as you go. Some of the coriander is added to today's meal, some will be for tomorrow's, but there's a lot that won't get used before I go away for five days and so it goes in the vegetable peelings pot, and will be buried in the garden tomorrow. A circle.