"You are a killer," Fred Trump would tell his sons. "You are a king."

From the time he was a child, Donald Trump knew that while he might have to answer to his father, he wouldn't have to answer to anyone else. With his father's money he created a private company — no board of directors was going to tell him what to do — and blasted his way through life as though rules, norms, and being accountable for your actions were for the little people.

And now, when he has become the most powerful person on Earth, Trump is finally getting a taste of accountability. And it's driving him nuts.

Trump's ability to escape accountability in his pre-political life wasn't just about being a wealthy white man, though that was certainly part of it. He learned from his father that certain rules just didn't apply to him. He got out of going to Vietnam because unlike your average Joe, "I had a doctor that gave me a letter — a very strong letter on the heels." Those debilitating bone spurs didn't stop Trump from competing in multiple sports, and to this day he can't remember which of his feet was so terribly afflicted. When the federal government sued Fred and Donald for refusing to rent to racial minorities, they negotiated a consent agreement — no fine, no admission of wrongdoing, just a pledge to do better in the future.

The lesson sunk in, helping Trump to develop a willingness to go where others with some sense of propriety or ethics wouldn't dare. He could take on huge debts and then leave others holding the bag, he could skirt rules and laws whenever it suited him, he could take a wife (or two or three), cheat on her and then discard her for a younger one when he got bored, and through it all maintain his celebrity and his lifestyle. When you're a star, as he later said about his ability to sexually assault women with impunity, they let you do it.

Whenever anyone Trump had wronged tried to fight back — a small business owner he stiffed, a woman he abused — he had the lawyers handle it. Sometimes a threatening letter was enough to make the problem go away, or he might sue them (before running for president Trump had sued someone or been sued a mind-boggling 3,500 times). At worst he'd make a payoff, for a sum that was meaningful to his antagonist but miniscule to him, like the $130,000 paid to the porn star Stormy Daniels to allegedly cover up their affair. The routine was familiar, handled almost entirely by his underlings, and left him free to continue acting the way he always had.

Trump's ability to escape accountability reached its apotheosis with his presidential run, in which again and again he did and said things that everyone told him would destroy his campaign, but never did. Every appalling statement, every fight he picked, every person he offended — and how he emerged unscathed every time — reinforced the old lesson: I can get away with anything.

But then he walked into the Oval Office and found that the presidency is surrounded by layers of accountability and constraint. The courts can overrule his policy choices. Congress has to be convinced to put his preferences into law. When he does something stupid, there's a good chance that one of his own aides is going to whisper it to a reporter. In just the latest example, on Tuesday Trump was handed briefing materials by his national security staff in preparation for a phone call with Vladimir Putin, on which the words "DO NOT CONGRATULATE" were written in all caps, lest Trump seem to validate Putin's corrupt election win. Naturally, Trump proceeded to congratulate Putin, and by the next day the story was in The Washington Post, making him look like a fool, a Putin lackey, and someone who gets treated like a child by his own staff.

Meanwhile, he's getting sued by multiple women over sexual misconduct, and worst of all is that diabolical Robert Mueller. Someone who doesn't care when Trump insults him, who can't be threatened or intimidated or sued or bought off, and who has the temerity to demand that Trump answer questions and turn over documents. Just who the hell does this guy think he is?

One gets the impression that what galls Trump the most isn't that Mueller is running a "witch hunt" trying to uncover evidence of wrongdoing when Trump's behavior was obviously above reproach. It's that Mueller just keeps going, turning former Trump associates, handing down indictments, and getting answers to his questions. Trump's only recourse is to fire Mueller, and everyone around him keeps telling him it would be a disaster if he did.

So for now Trump just has to take it. There may never have been anyone in Trump's life who imposed the kind of accountability on him that Mueller threatens to. Trump's tweets about him are cries of impotent rage, coming from a man realizing for the first time that there's another person out there who can make him answer for what he's done.

Just imagine how angry he'll be if Democrats take back the House in November and start handing out subpoenas to everyone who works for him. Then he'll really start to know what accountability feels like. And he isn't going to like it.