It was presumably a play on the expression, not something they thought was the common expression.

plays on words are great, except when counterfactual, and Rome did fall in a day, 6 times

That is not what is meant by the phrase “the fall of Rome”, which refers to the end of the western Roman Empire.

It's like quitting smoking. If you're very good at quitting smoking, because you already quit 6 times, it means the first 5 times you haven't really quite. If Rome fell 6 times it also means at least 5 times it didn't fall for good and thus it took more than a day to fall for good.

but the phrase is "Rome was not built in a day", nobody says Rome did not fall in a day

https://duckduckgo.com/?t=ffab&q=rome+did+not+fall+in+a+day&...

If you want to make the case that Rome did not fall in a day, that's fine, you may have even made the case in your comment. I was just commenting on using the stock phrase wrong and expecting it to resonate.

For example, I can say "An apple a day sends you straight to the doctor." If I said that, most people would recognize that I had twisted the original phrase, and could decide if they wanted to engage with what I wrote. But if I wrote, "just like an apple a day, gluten every day will send you to the doctor", I'd expect more pushback from people, "hey, wait a minute, that doesn't make sense"

> When dealing with issues like "the Sack of Rome", they pretty much did take place on particular days

I’d took much more than one of those for Rome to fall. Which was the point.

That wasn’t the fall of Rome, though, not really. There’s a reasonable argument that the fall of Rome started in the first century BC, when the Republic destabilised, culminating in Marius, Sulla, Caesar and friends, and ended in the 15th century AD or so.