I must be the BIGGEST tool ever...I do not like it at all when people pop by unannounced. It bothers me. Especially if I am feeling nervous or anxious.
- I disconnected the doorbell. I cannot stand the sound of it. It's very jarring.
- I also have a very specific ring on my phones, and I turn my phone ringer off as soon as I leave the office. I can see the blinking light so if someone calls, I am aware. If I am asleep, the phone ringer is definitely OFF.
- I do not answer the door if I am not expecting the person.
In my previous situations, I lived in very quiet, residential neighborhoods. Unfamiliar cars could be spotted a mile away. In fact, street parking was quite unusual. And there was no reason anyone would come by unannounced (simply based on manners alone).
I currently live in a beach city crammed with apartments and single family dwellings. I learned through experience that if I leave my door open, for some reason, people seem to take it to mean that they are invited to pop by whenever, for whatever reason

Also, I ended up becoming the neighborhood pet sitter, so I put the brakes on that, as well.
Mostly, I don't answer because I don't want to be bothered. Unless someone is screaming or calling for help. Then, of course, I will make myself available either in person or by calling 911.