I recently had occasion to reside, temporarily, and for unremarkable reasons, in a rented apartment in the Scottish town of Dundee. The lobby of the apartment b

I recently had occasion to reside, temporarily, and for unremarkable reasons, in a rented apartment in the Scottish town of Dundee. The lobby of the apartment building was accessed through a single door, with handles on both sides. Adjacent to the handles, there was also, on each side of this door, a hand-scribbled sign reading “Push”. Needless to say, I pulled. The door did not open. I pushed. The door did not open. I pulled again. The door opened.