Ketchup lives in the cupboard and other wars
No one has ever changed their mind about where ketchup lives. People have changed religions, football teams and genders more readily than they have moved the red bottle from cupboard to fridge or back.
Food rules are like this because they are inherited, not chosen — each one is a little flag of the house you grew up in.
Ketchup: fridge?
It escalates. Milk before or after the teabag. Beans touching the eggs. Pineapple's citizenship status on pizza. Every household treaty is one dinner guest away from collapse.
And the strongest opinions belong, reliably, to people who cannot cook.