Just outside the spacious corner office of the White House national security adviser, aides crowded into a windowless anteroom knew to make themselves small when John Bolton got a summons from President Trump. Bolton, his ubiquitous yellow legal pad in hand, would throw open his door and set off at a gallop.

Once in the Oval Office, Bolton would take copious notes on that pad, at times angering a president known to mistrust note-taking by even his closest aides, according to a former senior administration official…

[A]nother former senior official, one of several who spoke on the condition of anonymity to discuss internal matters, said Bolton “didn’t need to have” documents or his own notes from inside the White House, “since he probably went home every night and wrote about it.”

Noting the rapid completion of Bolton’s book, “I’m convinced he was writing all the time” he served as national security adviser, said this former official, who described Bolton as a nose-to-the-grindstone person who rarely socialized.