What if you do? In my experience in small European towns, shops close up at 5:00 or maybe a bit later but if you remember at 10:00pm (or on Sunday) that you need milk for the morning you are SOL.

The other responses are reasonable but disingenuous. The truth is you drive anyway. We have a fantastic drunk driving culture in America. It's really disappointing.

In much of the country, you either have it delivered or you go without it. There's commonly no reasonable way to get to a store without a car.

I'm just moving to the suburbs but I had to specifically go looking for one with shops in walking distance. It's far from the norm; I've lived in places before where the only way to a shop was along a major highway and it was too far to reasonably walk unless you had no choice.

Then you wait until tomorrow so you can drive half an hour to the Wal Mart. Or get it delivered. There are also places like Dollar General and gas stations which sell essentials for incredibly inflated prices nearby that you could walk to (but can still be miles away)

You take the car to the nearest big box store, mart, etc... usually miles away.