Trump began his presidency on a traditional note, with an inaugural speech hinting at the virtue of meaningful collaboration. “We, the citizens of America, are now joined in a great national effort,” he said, “to rebuild our country and to restore its promise for all of our people.”

Since then, Trump has reverted to his old fatalism.

“We’ll see what happens with Iran,” Trump said Sept. 5. “Whether they want to talk or not, that’s up to them, not up to me. I will always be available, but it doesn’t matter one way or the other.”

This philosophy springs from the privilege that’s defined his life, theorizes Tim O’Brien, author of “TrumpNation: The Art of Being the Donald.” The president was born into wealth, inherited business and opportunity, and kept graduating to higher stations despite financial, personal and political blunders.

“He profoundly believes nothing matters because he usually isn’t the victim of his own mistakes,” O’Brien says. (The White House did not reply to a request for comment.)