Starting in late 1985, Schwartz spent eighteen months with Trump—camping out in his office, joining him on his helicopter, tagging along at meetings, and spending weekends with him at his Manhattan apartment and his Florida estate. During that period, Schwartz felt, he had got to know him better than almost anyone else outside the Trump family. Until Schwartz posted the tweet, though, he had not spoken publicly about Trump for decades. It had never been his ambition to be a ghostwriter, and he had been glad to move on. But, as he watched a replay of the new candidate holding forth for forty-five minutes, he noticed something strange: over the decades, Trump appeared to have convinced himself that he had written the book. Schwartz recalls thinking, “If he could lie about that on Day One—when it was so easily refuted—he is likely to lie about anything.”
"The New Yorker: Trump’s Boswell Speaks"