I don’t recall ever hearing the phrase “social distancing” prior to March or possibly late February of this year.
A search reveals that it’s a technical term that was in use long before that, by virologists and other public health experts, most often in conjunction with warnings to the public during flu season.
Nevertheless the phrase had gained basically no traction in the English-speaking world, as these stats regarding its appearance in the Nexis English-language news data base show:
Total number of items in which the phrase “social distancing” appears:
August 2019: 7
December 2019: 10
All these stories were about seasonal flu (The August ones were from Australia and New Zealand, where flu is a much bigger problem during the summer than in the winter oddly enough. Not a lot of people know that).
January marks the first use of the term in stories about COVID, at a rate of and by the middle of the month the term is showing up five to ten times a day (144 uses for the month).
This rate stayed about the same for the first couple of weeks of February. Then:
Appearance of “social distancing” in English-language news media per day:
3/17: 10,000+ (Nexis doesn’t give a more exact number once it finds 10,000+). It remained at 10,000+ stories every day for several weeks.
8/14 (last day for which full data are available): 7,354
Note that these numbers suggest that there are tens of thousands of English-language news stories being published every day about the COVID epidemic, as of course only a minority of such stories will use the phrase “social distancing.”
In trying to assess whether COVID will, like the influenza pandemic of 1918-19 be mostly forgotten within a few years as a matter of cultural memory, I think it’s important to consider that this story has completely dominated the entire English language news media across the world for more than five months now, and will likely continue to do so for several more months at least. (I don’t know what the numbers would look like for non-English language media, but the increasing dominance of English as the world language of science, commerce, etc. makes these statistics especially significant).
I’m no media expert, but I would be surprised if there has been a comparable story in this regard since World War II.
In other words, no matter how this story turns out, my guess is that it will be a central part of our cultural memory for at least a generation or two — and especially in the United States, where the federal government’s catastrophic response will remain the defining moment of Donald Trump’s catastrophic presidency.