I'd just come back from spending five days in "Xanadu New Town" teaching English, four hours in a taxi. I pressed the wrong button in the lift, not realized it, was on autopilot and not looking at the numbers. All the landings and front doors in the place are identical. It finally dawned on me when I looked up at the apartment number above the door. "1802". I live in 1702....
People trying to get into the wrong house or apartment could be a real problem sometimes, because they actually could get in occasionally. When they built some of these places, they often fitted cheap locks with a very limited number of key combinations. I heard when they built a new housing area in my hometown in the UK,
someone found they could unlock every twelfth front door using their own front door key.i.e. apparently there was only twelve key combinations for the locks they used.