Yes and no. Where I grew up, we never locked the door. And when we went away, we even put a broom against the door to show everyone not to bother come visiting, since we're not home.
Here where I live now, no. The door is always locked so that you either need a key or or two hands to open it from inside. Standard.
Have you ever gotten too much change at a purchase and just shut up about it since the person selling didn't realize. How much?