So President Donald Trump has discovered that being president is a hard job – harder even than being a reality TV star and real estate brand-builder.

"I loved my previous life. I had so many things going," Trump told Reuters in an interview. "This is more work than in my previous life. I thought it would be easier."

This particular revelation may be shocking but it shouldn't be surprising. This is the man who asserted before taking office that "I could actually run my business and run government at the same time." And while he may have abandoned his "previous life" to some degree, he's still executive producer of "Celebrity Apprentice" (a role that by one estimate is paying him millions of dollars even now) and spends many a weekend golfing at Mar-a-Lago.

But more broadly, Trump's admission that presidenting is hard is just the latest in a long line of indications that Trump was yugely, massively unprepared for the office he sought last year. I don't think it's a stretch to say that he was more unprepared than anyone elected to the office before.

It's not simply a question of his various flip-flops since coming into office, but the sheer number of nontrivial issues on which he's admitted to having been oblivious.

Consider the litany of things that were apparently astonishing to the new president which would come as a surprise to no one who has paid more than a passing amount of attention to national and international affairs (or, having decided to run for president, started trying to get up to speed):

Trump was "all set to terminate" NAFTA on Saturday, he told The Washington Post on Thursday. "I looked forward to terminating. I was going to do it." What changed his mind? One of his cabinet secretaries showed him a map illustrating the damaging effects of ending the free trade agreement. Newly minted Agriculture Secretary Sonny Perdue "even brought along a prop to the Oval Office: A map of the United States that illustrated the areas that would be hardest hit, particularly from agriculture and manufacturing losses, and highlighting that many of those states and counties were 'Trump country' communities that had voted for the president in November," the Post reported. Oh. Well then. "It shows that I do have a very big farmer base, which is good," Trump told The Post. "They like Trump, but I like them, and I'm going to help them." Good thing Trump figured that out before pulling out.

Appearing at a news conference with NATO Secretary General Jens Stoltenberg on April 12, Trump declared that – contra his pronouncements during and after the presidential campaign – NATO was "no longer obsolete." Later in the month, talking to the Associated Press, he explained his shift: "So they ... asked me about NATO, and I said two things. NATO's obsolete – not knowing much about NATO, now I know a lot about NATO – NATO is obsolete, and I said, 'And the reason it's obsolete is because of the fact they don't focus on terrorism.' You know, back when they did NATO there was no such thing as terrorism." It's true that terrorism was not a pressing concern when NATO was established at the dawn of the Cold War, but the organization has been a key ally in fighting terrorists in places like Afghanistan since 9/11. His other NATO complaint was that its members don't spend enough on defense. But as The New York Times' Peter Baker has observed, "the alliance has hardly changed in three months. Just three more members out of 28 have committed to raise military spending to target levels by next year." (And despite what Trump seems to think, Germany does not owe NATO "vast sums of money.") But the larger point here is that Trump was making dramatic pronouncements about important issues of which he admittedly had little knowledge.

"After listening [to Chinese President Xi Jinping] for 10 minutes, I realized that it's not so easy" for China to control North Korea, Trump said in an interview with The Wall Street Journal (also on April 12). Trump, of course, got his history lesson wrong: "Korea actually used to be part of China," he said. It wasn't. In the same interview, Trump reversed course on his assertion – which he'd repeated just days earlier – that China is a currency manipulator. He also seemed to link his willingness to take a softer line with China to the need for that country's cooperation vis a vis North Korea. "Now, I did say – but you want to make a great deal? Solve the problem in North Korea," he said. "That's worth having deficits. And that's worth having not as good a trade deal as I would normally be able to make." Which is fine – but the idea that not starting a trade war with China might be helpful for getting their cooperation with North Korea is not exactly revelatory.

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In that same Journal interview, Trump also reversed course on the Export-Import Bank. Why? Here's his answer, in full: "I will tell you what, I was very much opposed to Ex-Im Bank, because I said what do we need that for IBM and for General Electric and all these – it turns out that, first of all lots of small companies will really be helped, the vendor companies, but also maybe more importantly, other countries give it. And when other countries give it, we lose a tremendous amount of business. So instinctively you would say it's a ridiculous thing but actually it's a very good thing and it actually makes money. You know, it actually could make a lot of money." That's a fairly standard argument in favor of the Ex-Im Bank. There are perfectly defensible positions for and against it, but what Trump said was that he'd never really given the issue more than a superficial amount of thought before entering office.

Meeting with German Chancellor Angela Merkel in March, Trump exhibited stunning ignorance of how trade works with the European Union. "Ten times Trump asked her if he could negotiate a trade deal with Germany. Every time she replied, 'You can't do a trade deal with Germany, only the EU'," a senior German politician told The Times of London. "On the eleventh refusal, Trump finally got the message, 'Oh, we'll do a deal with Europe then.'" Oh, well then. Sure. But it might have been a good idea for him to have some knowledge of this before he campaigned on dismantling the global order of multilateral trade agreements the U.S. has spent decades constructing in favor of bilateral agreements that, he now knows, he can't even make.

Remember Trump's bombshell (and baseless) accusation that President Barack Obama had had Trump Tower wiretapped during the campaign? "So much of this is new to Mr. Trump that only after he publicly accused Mr. Obama of having wiretapped his telephones last year did he ask aides how the system of obtaining eavesdropping warrants from a special foreign intelligence court worked," The New York Times' Peter Baker reported earlier this month. The same piece listed other items in the education of the president: "At first, Mr. Trump dismissed the importance of receiving his intelligence briefing every day, arguing that he did not learn much. … [A]s seasoned hands got access to him, he retreated from some of his provocative promises. He delayed his vow to move the American Embassy in Israel to Jerusalem after King Abdullah II of Jordan rushed to Washington to warn him of a violent backlash among Arabs. He abandoned his intention to bring back torture in terrorism interrogations after Defense Secretary Jim Mattis told him it was ineffective.

And, of course, there's this classic: "Now, I have to tell, it's an unbelievably complex subject," Trump told a meeting of the nation's governors in February. "Nobody knew health care could be so complicated." I don't go too far out on a limb when I say that the nation's governors knew that. So did members of Congress. And, really, anyone who has paid attention to politics for the last nine years ... or quarter century ... or more. Not for nothing, Trump's abject lack of knowledge on the topic affirmatively hurt his efforts to repeal and replace Obamacare. As one congressional aide told CNN: "If you are going to be a great negotiator, you have to know about the subject matter." Instead, Trump's view was: "Forget about the little shit."

None of this should come as a surprise. Asked by Time's Michael Scherer about his serial mistreatment of facts, Trump defended himself by suggesting that his nose for truthiness is superior to actual truth: "I'm a very instinctual person, but my instinct turns out to be right," he said.

And at some level I suppose it's commendable when a president is willing to admit the limitations of his own knowledge. That's especially true of this president, given his general penchant for denying ever having been wrong; though look back at the list above and you'll see that his changes of mind are generally predicated on new developments that are not new (NATO and terrorism) or are presented as some sort of epic revelation no one could have seen coming (health care is complicated).