“There’s just something about this job as President . . .” George W. Bush observed last week, in an interview with NPR. “You think one thing going in and then the pressures of the job or the realities of the world, you know, are different than you thought.” Bush wasn’t reminiscing about his own Presidency; he was “opining,” he said, about the current one. The reality that Bush had in mind—the one that he hopes President Trump will embrace—is that it is in America’s national interest “to be allies with Mexico and not alienate Mexico.”

Trump, of course, has invested a great deal of energy in denying that particular reality—along with many others, from the existence of climate change to the role of Russian meddling in last year’s Presidential election. Yet, in recent weeks, Trump has conceded that he might, in fact, have been wrong about a thing or two, and now stands corrected. “It turns out” and “nobody knew” are two of the signal phrases by which Trump indicates that an epiphany has arrived: that health-care policy is “so complicated,” or that North Korea is not a Chinese client state. “After listening [to President Xi Jinping, of China] for ten minutes, I realized it’s not so easy,” Trump told the Wall Street Journal earlier this month. Never mind the obviousness of these statements, or Trump’s weird guilelessness in presenting them as insights; they are being received, by some, as signs that Trump is growing in office. “I think President Trump is learning the job,” Mitch McConnell, the Senate Majority Leader, said last week.

Learning the job, in fairness, is a big task for any new President. “Regardless of his prior training, nothing he has done will have prepared him for all the facets of that job,” Richard Neustadt, the great scholar of the American Presidency, wrote in “Presidential Power,” his influential study, in 1960. All Presidents, he argued, enter office ignorant, innocent, and arrogant—liabilities it can take two, three, or even six years for them to overcome. Some never do. Neustadt saw “a certain rhythm” in the Presidential learning process, and, indeed, in most cases, it follows a well-worn path: the chaotic cram session of the transition; the headiness and disappointments of the first year; the midterm elections in the second (a “shellacking” of the President’s party, as Barack Obama described it in 2010, tends to dispel any lingering arrogance); and, of course, the crises—domestic and foreign—that come without warning. The education of a President is episodic, driven by events. The results, as we know, are uneven. They depend not only on fate but on the answers to three basic questions: what are the “particulars of [a President’s] ignorance,” in Neustadt’s phrase; does he have the humility to acknowledge them; and does he have the capacity—political, moral, intellectual—to address them?

John F. Kennedy faced all these questions. He entered the White House well prepared despite his youth: he had served fourteen years on Capitol Hill, had commanded, with distinction, a Navy torpedo boat during the Second World War, and had spent the better part of his life studying and exercising power. Yet, during his first few months as President, his particular ignorance emerged: an excess of trust in the C.I.A. and the Joint Chiefs of Staff, who convinced him, despite his doubts, to approve an invasion of Communist Cuba by a brigade of exiles. Kennedy hesitated; he asked tough questions of his briefers, but, in the end, he acceded, taken in by their optimism. The instant and utter failure of the invasion at the Bay of Pigs, in April, 1961, filled Kennedy with self-doubt and self-blame. “It is a hell of a way to learn things,” he said over lunch with James Reston, of the Times, and Arthur Schlesinger, Jr. But he did learn things, and soon changed things, as well: he not only replaced the leaders of the C.I.A. but also, from that point forward, regarded intelligence estimates and military plans with far greater skepticism. The historian Robert Dallek, in his biography of J.F.K., writes that Kennedy saw his missteps as “object lessons in how to be more effective. His resolve stood him in good stead: he managed coming crises”—most significantly, the Cuban Missile Crisis of the following year—“with greater skill.”

Bill Clinton, too, stumbled out of the gate. “Clinton terrified me,” one of his policy advisers, Bill Galston, later confessed, “because he almost always knew a good deal more about the subject, or at least some aspect of the subject, than you did.” Yet the disorder of the White House during Clinton’s first year—the famously long meetings that circled an issue but never really resolved it—raised the question of whether his intellect was always an asset. Clinton had a lot to learn in a hurry: about managing (and allowing himself to be managed by) the White House staff; about the hostility of the press corps and the snobbery of the Washington establishment; about the ideological stalemate in Congress; and, not least, about U.S. leadership in a shifting, often perplexing, post-Cold War world. Anthony Lake, his national-security adviser, and Warren Christopher, the Secretary of State, urged Clinton to get more engaged in the foreign-policy process and to conduct himself as Commander-in-Chief. “It took a while for Clinton to do the commander bit, which is to say issuing orders crisply,” Lake recalled in an oral-history interview. “It’s in the little things.” It was also in the big things: in August, 1995, after two years of discussion and delay, the Clinton Administration decided to act against Serbian aggression in Bosnia, and led a successful NATO bombing campaign. By 1996, Clinton was more sure of his footing on the global stage. The Times—which had been quite critical of Clinton’s conduct of foreign policy—endorsed his bid for reëlection, noting that he was now “regarded internationally as a leader with a sophisticated grasp of a superpower’s obligation to help the world manage its conflicts and economic contests.”

What is Trump’s particular ignorance? It is not a stretch to say that Trump knows less about policy, history, the workings of government, and world affairs than any of the men who preceded him as President. Trump’s ignorance sends historians and commentators scrambling for sufficient adverbs: to Daniel Bell of Princeton, Trump is “abysmally” ignorant; to Josh Marshall, of Talking Points Memo, he is “militant[ly]” so. “Proudly” is another popular one. Last summer, Trump told the Washington Post that he doesn’t need to read much because he makes great decisions “with very little knowledge other than the knowledge I [already] had, plus the words ‘common sense,’ because I have a lot of common sense.” The problem is not just what Trump doesn’t know; there is an expanding, alternative universe of things he imagines or insists to be true, from his claim that “millions” of illegal immigrants gave Hillary Clinton her victory in the popular vote to his charge that President Obama ordered a wiretap of Trump Tower. “He has made himself the stooge, the mark, for every crazy blogger, political quack, racial theorist, foreign leader or nutcase peddling a story that he might repackage to his benefit as a tweet, an appointment, an executive order or a policy,” the Los Angeles Times editorial board wrote earlier this month. Trump is somehow both credulous and cynical; if he were “mugged by reality,” in the old, conservative cliché, he would pin it on Obama, or perhaps Arnold Schwarzenegger.

This is not to say that Trump is incapable of learning in office. His recent changes of tone, opinion, and direction—on the importance of NATO, for example, or U.S.-China relations—might be signs that his thinking is evolving. They could also be tactical moves, or head-fakes, or further evidence that—unmoored from any core convictions—he is easily swayed by certain advisers. Whatever the case, it is one thing for Trump to acquaint himself with reality; it is another thing to know what to do about it. The singular burden of the Presidency is not merely to acknowledge obvious facts; it is, as Neustadt wrote, to determine a course of action “when conventional wisdom fails, the experts disagree and confusion dominates.” It turns out this job is not so easy.