I do that, Patsy. I check for green vegetables and cookable raw ingredients in other people's trolleys, and feel odiously smug when I see microwavable dinners, pizzas and crates of Coke. I've sometimes sent my poor husband back into the aisles from the checkout to get an item I've spotted in front of us in the queue. He's very tolerant, but I sometimes wonder if he's secretly like to eat junk food and fewer casseroles and stews! Trouble is, junk food and ready cooked stuff is more expensive, and I like to cook.