Exactly live in rural Midwest. Most vehicles and houses are left unlocked 24 / 7. If you forget you wallet you can still buy things and just come back later to pay. Don’t get me wrong lots of problems in the rural parts but something about how people relate does feel more human or natural IMO.

When you say leave the door unlocked, do you mean while you are in the house or away?

I encountered this when someone was talking about where I live as being the kind of place where you could leave the door unlocked. Everyone thought that seemed overstating it because you'd only really do that if you were going out for a few minutes. We were quite shocked to hear they were talking about locking the doors while they were home. None of us had even considered that as a meaning even though it was the norm for where they came from.

For many years, where my grandmother lived (in Lexington, TN), she kept her front door unlocked. This was long after my grandfather had passed away. She still had neighbors who might need to come in and borrow some butter or something.

After a long time, she started locking the door. But she left a copy of the key in the mailbox next to the front door. That was also for her, in case she went out and lost her keys or forgot where she put them.

It was only a few years before she passed away that she had the key taken out of the mailbox.

My wife (before we were married) was visiting her grandparents in a town in western Pennsylvania. Not a large town, but not all that small, either. They were going out to lunch or dinner or something. My wife was the last one out, and locked the door. When she found out, her grandmother said, "Oh. I hope I've got the key..."

Then never locked the door, even when going out for an hour+ and leaving nobody home.