A handwritten list shows which needs were important before the shop began making suggestions.

A list written at the kitchen table is a record of what you actually needed, made in a calm place with no one selling you anything. Inside the shop, everything is arranged to add to it: the end of the aisle, the offer, the thing at eye level. The paper in your hand is the version of you that had no marketing in the room.

Write the list before you go and keep it visible while you shop. Add things if you genuinely want them, but notice you are adding. Comparing the trolley with the paper afterwards tells you plenty about how the shop is designed.