It would be nice if this was the case. In grad school I taught in a building that was on a hill and had once been separate buildings so different entrances were

It would be nice if this was the case. In grad school I taught in a building that was on a hill and had once been separate buildings so different entrances were on different floor and the transition between the former separate buildings was 4 stairs. So there was a floor with rooms numbered 1xx and 0xx. There was also a floor below the 0xx floor. They just numbered it 00xx. And you could enter the building on any of those floors depending on what door you picked. The class I taught was in 0005. Room 005 was someone's office. So on the first day of every semester we would have students waiting outside the door of 005 instead of 0005...