As you know, Trump spent his first weekend as president on vacation, but he apparently spent most of his very first day getting mad on Twitter.
According to the New York Times, two factions within the Trump regime tried to steer Trump on his first day in office and the faction that favored petulant rage won.
The lack of discipline troubled even senior members of Mr. Trump’s circle, some of whom had urged him not to indulge his simmering resentment at what he saw as unfair news coverage. Instead, Mr. Trump chose to listen to other aides who shared his outrage and desire to punch back. By the end of the weekend, he and his team were scrambling to get back on script.
The idea that they struggled to get "back on script" feels like a misnomer to me because there is no other script. This is it.
Trump is exactly the kind of person you think he is and the White House isn't going to change that. If anything, he'll get worse. His unparalleled narcissism cannot be satiated even by holding the highest office in the land. He desires to be worshiped.