Framed photos of President Donald Trump's parents, Fred and Mary, sit on a table in the Oval Office.

Editor’s Note: Michael D’Antonio is the author of the book “Never Enough: Donald Trump and the Pursuit of Success” and co-author with Peter Eisner of “The Shadow President: The Truth About Mike Pence.” The opinions expressed in this commentary are the author’s. View more opinion articles on CNN.

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Sometimes all the evidence you need to solve a mystery hides in plain sight. When it comes to understanding the man in the Oval Office, the evidence can be found over his left shoulder when he sits at the Resolute desk.

The two framed photos, one of his father and a smaller one of his mother, are the only family pictures President Donald Trump keeps close by. They are positioned so that his parents are often seen peeking in on their son, as he is photographed making a call, listening to aides or meeting with Kim Kardashian.

If you want to know why the President is so fixated on winning, look to the man – his father, Fred Trump – who taught him that Trumps were supposed to win at everything. According to biographer Harry Hurt III, Fred raised his son with the mantra, “You are a killer, you are a king.”

“That’s why I’m so screwed up,” Trump wrote in his 2007 book “Think Big,” “because I had a father that pushed me pretty hard.”

Indeed, people who knew the Trumps in Fred’s heyday confirmed as much to me, with several adding that Donald identified with his father from a young age. As Trump’s mentor Ted Dobias of New York Military Academy told me, Trump’s father was extremely tough – “very German” was how he put it – and he made demands his son had trouble satisfying. In fact, Donald was sent to the military school because he repeatedly failed to meet his father’s standards for how a boy should behave.

An echo of Fred’s harshness can be seen in the President’s cruel policies, including separating asylum-seeking children from their parents and causing the longest government shutdown, depriving 800,000 federal workers of their paychecks for more than a month.

The cruelty of the shutdown was expressed in a sample letter that the Office of Personnel Management sent to federal employees not getting paid. In an initial iteration of the letter (which the agency claims it mistakenly posted and has since amended), it recommended that employees offer to do manual labor, such as carpentry and painting, in lieu of paying rent to their landlords. While Trump may not have conceived of that terrible idea, it appears he has surrounded himself with bureaucrats who have adopted a similar style to dealing with challenges – showing little to no mercy.

Adding insult to injury, the Trump administration is recalling thousands of furloughed federal employees, forcing them to work without pay, to meet the needs of vital agencies, such as the Internal Revenue Service.

The shutdown, you will remember, began when the President suddenly reversed course on a budget deal that had already passed the Senate in December. Instead of keeping his word, he chose to listen to Ann Coulter and Rush Limbaugh – and announced he would veto future funding arrangements that fail to provide $5.7 billion to build a wall on the border with Mexico. (“I will take the mantle,” he said, when he agreed to own the shutdown.)

The wall, which be promised voters would be funded by Mexico, is more of a symbol than actual border protection, but after more than a month, it’s clear that it is a symbol he will pursue no matter how much pain he inflicts on workers, their families, their communities and even everyday Americans who aren’t getting the government services they have paid for with their taxes.

To get a sense of how far Trump will go when it comes to threatening others, consider the threat he made against the 11 million undocumented immigrants now living in the United States. In a recent Twitter fit that drew House Speaker Nancy Pelosi into the issue, he said there would be “no big push” to remove them, and then added, “but be careful Nancy!” The message was clear: Do what I say, or the immigrants will pay the price.

Pelosi vexes Trump because she is the one politician who seems to know how to play his game. One source of her strength is obvious: She is the only Democrat who controls part of the government. But there’s more to it than that. Pelosi is a strong woman of the sort who could have taught a young Donald important lessons that Fred and Mary, his mother, failed to impart.

Pelosi managed a gaggle of five children who were so rambunctious, said one daughter, “She couldn’t get anyone to babysit.” It was up to her to impose order and impart lessons on how to get along with others. For much of his childhood, Trump didn’t have such a person in his life, and the deficit shows.

Though Trump was heavily influenced by his father, his mother played a smaller role. For much of his young life, Mary was ill. His friends from that era told Politico writer Michael Kruse that while they often saw Fred or the housekeeper around the house when they visited, Mary was little more than a “ghost” in the record of the President’s life.

Limited as Mary’s role seems to have been when he was a boy in Queens, New York, her presence became even fainter when, at 13, he was dispatched to New York Military Academy. There, he lived in a world where women were almost nonexistent, and a pseudo-military type of masculinity prevailed.

As Trump’s school friend Sandy McIntosh told me, the military school was all about hierarchy and male chauvinism. No one should be surprised by McIntosh’s recollection that the only female role models who got real attention at the school appeared in the pages of Playboy.

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    As a result of Trump’s childhood experiences, the now 72-year-old man with five children and nine grandchildren, keeps the images of his long-deceased parents within sight in his office. These are the people he sought to please through his troubled childhood that led to military school and an adult life marked by broken marriages, busted businesses and ridicule at the hands of the New York tabloids.

    They were likely the ones who deprived him of the leavening agents – compassion, generosity and a sense of responsibility – that would have made him a better man and an even better president. In their absence, he is a leader who, when the going gets tough, says, “The buck stops with everybody.”

    Trump’s insatiable ego, callous disregard for the future and his inability to take responsibility have now become his defining characteristics. Sitting in the Oval Office, with the unfinished business of his past staring out from framed photos, he appears to drag the nation continually through his psychodrama. He knows that his father expected him to win, at everything, and he largely has. But what his mother expected of him is not clear, perhaps even to Trump himself.