The other thing about "shopping with a list" and buying ONLY what is on the list is that it eventually costs you money, not only the gas to go back and buy things you forgot, but the inability to take advantage of sales that you didn't know about. Let's say your family uses 2 pounds of butter a month. Butter is usually $3.50 per pound. If butter isn't on The List, then you can't take advantage of the manager's special sale where it's $2 per pound. (Butter freezes nicely, BTW.)
Far better is to make up weekly menus, then buy the stuff that you use for that week's menu. Eliminate most of the snack food impulse items, like cookies and chips and candy.