We were heading for Potchefstroom, so the wagon needed filling. After the petrol-oil-water-tires-windscreen routine was complete, I gave the attendant the money and he asked, as excitedly as if he were proffering a gift, would I like a cash slip? I told him I didn’t. A few minutes later, he returned with a handful of notes, coins, and – a cash slip. Filling up in Kroonstad, we went through the same petrol-oil-water-tires-windscreen ritual minus the oil-water-tires bit. I handed over the cash, and was asked the same cash-slip question. Again, I said “No, thank you.” And sure enough, a few minutes later, he returned with some notes, some coins, and – a bloody cash slip! Perhaps petrol attendants go through some kind of training to become like this. “Listen, when the driver says he doesn’t want a cash slip, he’s lying. They always lie. So, give him a cash slip. Understand? The driver simply doesn’t know whether he wants a cash slip or not. So, give him a cash slip anyway.” A number of questions crossed my mind. The first was about the army. What would happen if, given the instruction to turn left, the troops simply ignored the order? My second, less frivolous, thought also took the form of a question: how many hundreds of thousands of trees are being hacked down daily all over the planet, so that the world’s petrol attendants can give you a cash slip you don’t want. My third question was: why do some of the sales slips I’ve received lately comprise not one but three pieces of paper, two the size I’ve just mentioned and a third about twenty centimetres long? The cashier’s life history, the purchase date and the time (to the last second), every item’s bar code – all organisationally crucial. Some slips are even from an organisation proclaiming its wholehearted commitment to environmental conservation. What hypocritical twaddle! I wonder how much these slips are costing the earth. After such thoughts, I needed a cup of coffee. As you would expect, it came with milk and sugar. And three sales slips …