Nobody knows everything, and certainly nobody who’s ever sat in the Oval Office has entered with a complete mastery of all the varied issues that land on the desk of the president of the United States.

But reading the transcript of Donald Trump’s recent interview with three New York Times reporters, two things stand out. One is the sheer range of subjects that Trump does not understand correctly — from French urban planning to health insurance to Russian military history to where Baltimore is to domestic policy in the 1990s to his own regulatory initiatives. The other is that Trump is determined, across the board, to simply bluff and bluster through rather than admitting to any uncertainty or gaps in his knowledge.

It’s an approach that’s certainly commonplace among Trump’s cohort of rich Manhattanites. People who’ve spent years surrounded by flatterers and lackeys eager to get their hands on their money tend to come away with an inflated sense of their own domains of competence. But precisely because the demands of the presidency are so unimaginably vast, it’s a frightening attribute in a chief executive.

The complete interview is a little bit hard to parse, since Trump keeps ducking off the record and the transcript interrupts. But it really is worth taking in the whole thing — the scope is breathtaking.

Trump doesn’t seem to know what health insurance is

Health care policy is very complicated, but most Americans have at least some passing familiarity with how health insurance works because most of us have health insurance.

Trump himself, meanwhile, has spent years as a top executive at a business that provides health insurance to its employees. So you would think that even if he were completely ignorant of every single topic of public policy, he would at least be aware that to provide a person with health insurance is expensive. It is, after all, an expense that his businesses incur:

TRUMP: But what it does, Maggie, it means it gets tougher and tougher. As they get something, it gets tougher. Because politically, you can’t give it away. So pre-existing conditions are a tough deal. Because you are basically saying from the moment the insurance, you’re 21 years old, you start working and you’re paying $12 a year for insurance, and by the time you’re 70, you get a nice plan. Here’s something where you walk up and say, “I want my insurance.” It’s a very tough deal, but it is something that we’re doing a good job of.

As Sarah Kliff notes, the idea that health insurance costs $12 a year is laughable.

For a sanity check, consider that if health insurance cost $12 a year, then for the government to provide insurance to all 330 million Americans would cost about $4 billion a year, or 0.22 percent of GDP. There would be nothing to argue about.

But even more remarkably, Trump doesn’t even seem to know what health insurance is. The idea of paying a small annual premium up until a given age, at which point you have the insurance policy free and clear, roughly corresponds to how a limited payment life insurance plan works. These plans are useful tax avoidance devices for extremely wealthy individuals, which is perhaps why Trump has them at top of mind, but it has nothing to do with health insurance.

Trump confuses two different Napoleons

On a wildly different subject, Trump reveals that he is unaware Napoleon I and his nephew Napoleon III were two different people:

TRUMP: Yeah. It was beautiful. We toured the museum, we went to Napoleon’s tomb … [crosstalk] TRUMP: Well, Napoleon finished a little bit bad. But I asked that. So I asked the president, so what about Napoleon? He said: “No, no, no. What he did was incredible. He designed Paris.” [garbled] The street grid, the way they work, you know, the spokes. He did so many things even beyond. And his one problem is he didn’t go to Russia that night because he had extracurricular activities, and they froze to death. How many times has Russia been saved by the weather?

Unlike the health insurance thing, Trump’s ignorance on this point is probably widely shared in the United States.

But Napoleon I ruled France for several years, invaded Russia, was defeated and overthrown, came back for a brief 100-day reign, and then was defeated at Waterloo and overthrown again in 1815. More than three decades later, the Revolution of 1848 brought his nephew Louis-Napoleon Bonaparte to power as president of the Second French Republic. He later staged a coup and set himself up as Napoleon III, emperor of France. And it was during his rule that Georges-Eugène Haussmann executed his famous renovation of the Paris streetscape.

The Napoleon whose tomb Trump visited did accomplish many things before his military defeat — including the creation of the civil code that is the foundation of almost every legal system on the European continent, and the spread of the metric system — but he didn’t design the Paris street grid. No doubt most Americans don’t know anything about Napoleon III, but in exchange, most Americans don't run around making confident assertions about the history of urban planning in Paris.

Trump misdescribes his tax plan

Back on the policy front, Trump says of his tax plan that “if you add what the people are going to save in the middle income brackets, if you add that to what they’re saving with health care, this is like a windfall for the country, for the people.”

Trump’s actual tax plan would raise taxes on millions of Americans while delivering a windfall to the rich.

Trump’s tax plan from fall raised taxes on 25+ million Americans. Today’s revisions appear to raise taxes on *more* families b/c SD smaller! pic.twitter.com/IUAcwLrB38 — Lily Batchelder (@lilybatch) April 26, 2017

According to the Tax Policy Center, the average American family would see its after-tax income rise by about $760, while families in the top 1 percent of the income distribution would see their incomes rise by about $175,000 — more than triple the total household income of the median American. Trump’s plan also features a big corporate tax cut.

To be fair to Trump, however, given how unpopular the idea of tax cuts for the rich and big companies is, it’s entirely possible that he is simply lying about this.

Trump doesn’t know American political history

Early in the interview, as a way of explaining how tough health care is as an issue, Trump observes that “Hillary Clinton worked eight years in the White House with her husband as president and having majorities and couldn’t get it done.”

Bill Clinton, of course, had congressional majorities for two years, not eight. And while it’s true that the 1993 drive for comprehensive health insurance reform failed, it’s simply not the case that Clinton got nothing done on health care. The 1996 Health Insurance Portability and Accountability Act, for example, is critical to the functioning of the job-based insurance market. It guarantees, among other things, that if you get sick while working one job and then later switch jobs, your new insurance plan can’t charge you a penalty rate for your preexisting health condition. The Clinton administration also created the State Children Health Insurance Program (SCHIP), which covered millions of children.

Trump also believes that “for the time in office, five months and couple of weeks, I think I’ve done more than anyone else.” And he clarifies that he means “not just executive orders” but bills passed by Congress.

By this time in his presidency, Bill Clinton had signed the Family and Medical Leave Act and the motor voter bill. George W. Bush had signed his first big round of tax cuts. Barack Obama did a major economic stimulus bill, the Lilly Ledbetter Act, and a significant SCHIP expansion. LBJ signed a big tax cut.

Some free advice for Trump aides who’d like to make their boss look less ridiculous is that he should argue that Ronald Reagan’s legislative agenda also got off to a relatively slow start but he nonetheless proved to be a very consequential president. There’s more to life than speed.

Trump also remarks that because of Obama’s Wall Street regulation bill, “people can’t get loans to buy a pizza parlor.” According to the National Federation of Independent Business’s small-business owners survey, only 4 percent of business owners report trouble getting credit.

Trump makes lots of weird, trivial errors

In the course of the interview, Trump also makes a lot of random little factual errors:

He says Japanese Prime Minister Shinzo Abe’s wife doesn’t speak any English, but she seems to speak English fine.

He says Deputy Attorney General Rod Rosenstein is from Baltimore, when he grew up in the Philadelphia suburbs and has lived for years in Bethesda, just outside of DC.

He says the FBI director “reports directly to the president of the United States,” which also isn’t true. In fact, the FBI director reports to the director of national intelligence.

He says the Russia investigation is “not an investigation” (whatever that means) and also that “it’s not on me” (it is).

He says James Comey wrote a letter to him, when he actually wrote a letter to his former colleagues at the FBI.

He says 51 Republican senators came to his health care meeting at the White House, when in fact Susan Collins and Rand Paul didn’t attend and John McCain was sick, so the number was 49.

Anyone can make mistakes, of course, but the sheer quantity of these kinds of mistakes is odd. The headcount issue is particularly puzzling, because one crucial difference between 51 and 49 is that if you can get 51 senators to agree to something, you can pass a bill, but 49 isn’t good enough.

Trump’s combination of ignorance and arrogance is dangerous

A troubling subtext to all of this is that Trump does not seem willing to concede on any level that his unorthodox background leaves him with some gaps in his knowledge relative to most previous presidents.

Instead, somewhere in the middle of mangling his discussion of health care, he interjects that “I know a lot about health care.”

The reality is that it’s not uncommon for a president to take office and not be fully up to speed on some aspects of the job. But ideally a new president will have learned, based on his prior experiences, how to get up to speed. Trump seems too insecure to admit any gaps in knowledge, and prefers to just kind of bluster and bluff ahead. Sometimes that involves saying things that are outright false, and other times it involves enigmatic remarks like, “I’ve given the farmers back their farms, I’ve given the builders back their land to build houses and to build other things,” that defy any kind of interpretation.

To an extent, Trump makes this rambling, digressive mode of talking work for him. He displays such ridiculous ignorance on such a wide range of things that it’s hard to squarely accuse him of lying about something like his tax plan. Oftentimes, it’s hard to know what he’s even talking about. But it all sharply raises the question of what on earth he’s going to do if he’s ever faced with a crisis that divides his advisers and has to make a decision about an issue he doesn’t understand very well.