In summer, the brick oven that was New York would sometimes get relief from tanker trucks passing by and spraying water into the hot, hot streets. This served to wash down the gutters, but it also sent out a glow of coolth that would rise up through the open apartment windows that had not yet invented air conditioning. Not all of the telephones were single-party lines, so there was a politesse that existed: If someone were on the line when you picked up the receiver, you did not listen in on your neighbor's conversation ... except, of course, when you did... and many phones had specific rings that indicated incoming calls ... two long rings and a short, perhaps, to let you know the call was for you.
As often as not, men wore ties, no matter how tattered their clothing. And men wore hats which they tipped to ladies passing ... or perhaps just of their acquaintance. Horse-drawn wagons were not common, but nor were they rare. The mail came twice or maybe three times a day. World War II, already in full swing in Europe, was just gathering momentum in the United States... and I was fortunate to have a blue tricycle made of metal.
All of it and more like it was not "on the cusp" of anything. It was just the way things were.
Now, of course, I can see that my childhood environment was on the cusp of whatever evolved in its wake. I can indulge in a wispy nostalgia or remember the medicines that did not exist or wonder how anyone got along without the Internet.
But I cannot look forward with the same assurance that I look back at the cusp of things. Surely I am once again on the cusp of something. What it is, I haven't a clue and could never possibly have one ... which makes me wonder why anyone outside TED talkers and politicians would even mention such things.