I’ve noticed this on the jobs that I’ve worked. I’m not sure why they think it’s so important. Maybe it’s because this door is my only means of getting in and out of my house at night. If I don’t have my keys, I cannot unlock my door without them.
This is true, Ive never been in a house in which there were no keys and Ive made this mistake on at least two houses. Even if you dont have a key, you probably have the code for the place. Ive never been in a house in which the door was locked. This is because it is a code, which is written on the wall or in the kitchen. If you see this code, you need to unlock the door.