Okay, the entrance to Pevensey 2 consists of a revolving door (that you have to push), and a couple of smaller side doors. Now it's very windy outside here today, and so those doors have been locked because of the winds (otherwise whenever someone opens them it blows a right gale through here. Because of various regulations and the fact that there is 24-hour access to areas in this building, those doors can be opened when locked from the inside by turning a knob (a bit like a front-door lock that locks behind you). Normally, however, they are unlocked and can be opened by pushing.
Quite a few people have gone and walked into those doors, expecting them to open. Never mind the piece of paper stuck to the door at eye level saying that they're locked. After some rattling of the door they eventually find the knob and open it.
A small handful have walked to the door, but read the notice and instead used the revolving door.
The majority either read the notice from a distance or were going to use the revolving door anyway.
Makes you wonder about how we percieve things, doesn't it?