The genius in the White House has always believed that what makes him special is his ability to get things done without going through the steps others must take.
In school, he bragged that he'd do well without cracking a book. As a young real estate developer, his junior executives recalled, he skipped the studying and winged his way through meetings with politicians, bankers and union bosses. And as a novice politician, he scoffed at the notion that he might suffer from any lack of experience or knowledge.
So when President Donald Trump tweeted last weekend that he "would qualify as not smart, but genius . . . and a very stable genius at that!" it was consistent with a pattern of asserting that he will do this his way, without bending to expectations about what constitutes proper presidential behaviour.
The tweet, issued in response to a new book that suggests his closest advisers doubt his mental stability, not only doubled down on his belief that smashing conventions is the path to success but underscored his lifelong conviction that he wins when he's the center of attention. In the ceaseless battle of life, Trump made clear by claiming the title of genius that he won't give way to those who believe he doesn't belong at the top.
"There is a certain kind of genius to winning the presidency like it was an entry-level job," said Dave Shiflett, the co-writer of Trump's first book about his political views, The America We Deserve, which was published in 2000.
"To go into those campaign rallies with just a few notes and connect with people he wasn't at all like, that takes a certain genius. His genius is he'll say anything to connect with people. He won by telling the rally crowds that the people who didn't like them also didn't like him."
To many people who worked with Trump throughout his career, this week's tweets - and Tuesday's virtually unprecedented Cabinet Room reality show, in which the President conducted an on-camera negotiation about immigration policy with stunned congressional Republicans and Democrats - were familiar tactics: a bold, even brazen, drive to put on a show and make himself the star.
Even when he is not overtly trying to win attention, his natural instinct - a form of genius to some, a sign of instability to others - is to choose the unfiltered path, as he did Thursday, when he told senators during a White House discussion about immigrants from Haiti, El Salvador and some African nations that the United States should bring in people from countries like Norway, not from "shithole countries".
The way we got things done was to approach him with an idea and make him think it was his. It was so easy.
Although Trump on Friday appeared to deny having used that vulgarity, he tweeted that he did use "tough" language - a long-standing point of pride for the President, whose political ascent was fueled by his argument that, as a billionaire, he is liberated to say what some other Americans only think.
From his earliest days in the real estate business, Trump boasted frequently about being smart, said Barbara Res, who was Trump's top construction executive when he built Trump Tower on Manhattan's Fifth Avenue in the 1980s.
"He needed to be stroked all the time and told how smart he was," she said. "Every decision process was clouded by his sense that he knows more than anybody else. But you could work with that: The way we got things done was to approach him with an idea and make him think it was his. It was so easy."
Res added: "Donald was always a forest person; he never knew anything about the trees. He knew concrete was brought in on trucks, but he really didn't know how to run a project. What he had was street smarts - good instincts about people."
Those who have watched Trump for decades say he has always encouraged people around him to view him as someone who could see things that others could not.
A.J. Benza, a former journalist who covered Trump for many years in New York and in 2001 had a public spat with him when Trump began going out with Benza's girlfriend, said that Trump often talked about being the smartest guy in the room.
"He never meant 'book genius' when he said it," said Benza, who now hosts Fame is a Bitch, a podcast about celebrity. "He means, OK, he didn't hit the brains lottery, but he's brilliant and cunning in the way he operates.
"He's amazing at taking the temperature of the room and knowing how to appease everyone. You want that kind of instinct in your quarterbacks, in your generals. It's not what we've ever thought of as what makes a great president, but he's never going to be the guy who makes great speeches. This is who he is."
Being something of a genius was central to Trump's self-image, his former executives said. Everyone around him learned to cater to that - even his father, who trained Trump to follow in his footsteps as a developer.
In the first major newspaper profile of Trump, in the New York Times in 1976, his father, Fred Trump, describes his son as "the smartest person I know".
Throughout his life, Trump has believed that his instincts and street smarts positioned him to succeed where others might struggle.
At the University of Pennsylvania, he concluded that "there was nothing particularly awesome or exceptional about my classmates" in the real estate division of the Wharton School's business program, Trump later wrote in one of his books.
"Perhaps the most important thing I learned at Wharton was not to be overly impressed by academic credentials."
Res said that Trump often bragged that he was "first" in his class in the Wharton program or that he was a "top student" there, but his name does not appear in the school's honor roll and classmates recalled him as someone who skated by doing little work.
"He did what it took to get through the program," classmate Louis Calomaris told The Washington Post in 2016.
His father often told Trump that "you are a king", instructing him to "be a killer".
Fred Trump was a student of Dale Carnegie, the evangelist of success through self-improvement, and an acolyte of Norman Vincent Peale, the New York minister who preached a gospel of positive thinking.
Never a strong student, Trump said that he came to believe he did not need to study as others did to make their way in the business world. Rather, he believed he had the inherent smarts to make the right decisions.
"I know in my gut," he said in an interview last year. "I know in 30 seconds what the right move is."
But that instinct was undermined, according to several former Trump executives, by his Lone Ranger style: "He can't collaborate with anybody because he doesn't listen to anybody," Res said. "He doesn't trust anybody, except his family. That's why [his former wife] Ivana was involved in everything and why now his children are too."
Trump said his father taught him about the mechanics of real estate development, as well as the softer skill of massaging the political system on behalf of his building projects. But he also believed he had something more: a genius for showmanship, a knack for surrounding himself with the trappings of success, thereby creating the perception that he was uniquely capable of big, bold action.
Genius and ego were both essential elements of success on a grand scale, Trump said. He told an interviewer in 1990 that every great person, including Jesus and Mother Teresa, found the path to success via ego: "Far greater egos than you will ever understand," he said.
"I believe in being prepared and all that stuff," Trump told biographer Michael D'Antonio. "But in many respects, the most important thing is an innate ability. I'm a big believer in natural ability," which, Trump said, he had "always had".
Throughout his business career, Trump expressed deep scepticism of book learning, scoffing at the notion that academics were smarter than others, contending instead that his instincts would prevail over those who studied a subject to death.
In 2000, when Shiflett co-wrote Trump's book on politics, a newspaper that was writing about the book asked what author had most influenced Trump. Shiflett said he called Trump's office to find out what he should tell the reporter, and he was told to pick any writer he wanted to.
"So I told them he likes Dostoevsky," Shiflett said. "It was all just good times; the spirit around him was kind of mirthful. Everybody understood that and nobody took any of it very seriously."
In Trump's vocabulary, "genius" is perhaps the highest praise, and it refers to a street-level ability to get things done. Trump often referred to his lawyer and early mentor Roy Cohn as "a total genius" or a "political genius", even if he was also "a lousy lawyer".
Trump explained in one of his books that his own true "genius" was for public relations: Rather than spending money on advertising, he said, he put his efforts toward winning news coverage of himself as a "genius".
Despite his long history of boasts and his many admissions that he has a large ego, Trump has also had moments of extreme self-doubt. Two of his biographers, Gwenda Blair and Harry Hurt, describe a period around 1990 when, as his marriage to Ivana Trump was breaking up, he occasionally spoke about suicide, according to friends and relatives.
Ivana Trump decided that the couple should see a psychiatrist. Her husband resisted at first, but then agreed, telling her he'd go, "only if you think it will fix what's wrong with you", according to Hurt's 1993 book Lost Tycoon: The Many Lives of Donald J. Trump. Hurt reported that the future president attended only one session.
Soon, he was back to his usual publicly bullish self, "Trump being Trump," as he sometimes called it.
"He says things because it gets attention," Shiflett said. "He just wants people to talk about him."