I've since paid more attention, and shall do so in the future. I found Irish people to be some of the nicest people in the world, and I just loved my time there, short as it was. I loved the North as well as the Republic. And I still don't know whether to call it Derry or Londonderry.
The hardmen on either side are the gable wall historians.
The London and Dublin establishments are horrified by the shenanigans but don't really know what to do.
It's also called the Maiden City or Stroke City. The latter has nowt to do with your health; it's the symbol in Londonderry/Derry.
The small habitation in the early 1600s was called Derrie - King James' officials used the Scottish language in the documents, not English. It was later named Londonderrie because the London companies had financed and built what later became the walled city we see now.
Partial historians such as Bold Fenian curiously enough use the English form of the name: Derry!