When Donald Trump says, “Nobody knew that” — or related phrases such as “A lot of people don’t know that” or “People don’t realize” — he’s generally referring to things many people already know, but which he only recently learned.

As a Washington Post analysis noted a couple of years ago, “Trump’s lessons are often accompanied by raised eyebrows, widened eyes and a ‘gee whiz’ look that suggests perhaps the nation is witnessing the president’s education in real time.”

As it turns out, we are still witnessing the president’s education in real time.

In an apparent attempt to put the virus in context, Trump also noted that tens of thousands of Americans die each year of the flu, a fact he said was new information for him: “Nobody knew that; I didn’t know that,” he said.

It was great to see and hear the two sentences combined this way. In Trump’s mind, he had no idea that so many Americans die annually from influenza, and as such, the Republican reflexively assumed that “nobody” else knew it, either.

Because for the president, if he didn’t know something, it stands to reason that no one knew it.

This has become an unexpectedly (and unintentionally) amusing part of his political persona. Occasionally, for example, Trump makes the “nobody knew that” declaration to make a point that’s false, but which he wishes were true. As regular readers may recall, then-candidate Trump insisted in 2016 that “nobody knows” that the murder rate is at 45-year high. In reality, nobody knew that because it wasn’t true. Trump has also argued that “a lot of people don’t know” that U.S. taxes are the highest in the world, which would be fascinating, if his point weren’t completely wrong.

Last summer, the president appeared alongside then-British Prime Minister Theresa May in London, where he said with confidence, “We are your largest partner. You’re our largest partner. A lot of people don’t know that. I was surprised. I made that statement yesterday, and a lot of people said, ‘Gee, I didn’t know that.’ But that’s the way it is.

It’s not the way it is. Trump had no idea what he was talking about.

But just as frequently, the Republican uses this and related phrasing to describe facts that many Americans already knew, but which are new to him.

Referring to the president as “Captain Obvious,” Dana Milbank noted a while back just how frequently Trump reflects on what he assumes others don’t know:

That Bill Clinton signed NAFTA: “A lot of people don’t know that.” What a value-added tax is: “A lot of people don’t know what that means.” That we have a trade deficit with Mexico: “People don’t know that.” That Iraq has large oil reserves: “People don’t know this about Iraq.” That war is expensive: “People don’t realize it is a very, very expensive process.”

At some point, the president is going to pay someone to ghost-write a presidential memoir, and I’d love to see it titled, “Nobody Knew That: The Donald Trump Story.”