I make my shopping lists at home. I base my shopping lists on what I already have, and what I want to cook this week. Pretty reasonable, I think.

Because I have a shopping list, I don't need to remember what I have in the fridge while I'm in the grocery store. I buy the things I need, and I leave.

The grocery list goes in Todoist, by the way. In case you were afraid that there was an aspect of my life with no apps involved.