Coupled with this is the revelation that the only way his staff can brief him is with short little tweet-sized sentences. On top of this, the linked article details about how Trump's incessant use of Twitter has actually now become dangerous.
Trump is famously arrogant and narcissistic. He think he's too smart to be outsmarted and has such superior skills and instincts that he doesn't need to be briefed or prepared for anything.
He also is known to eschew long, detailed meetings and extensive briefings. He wants very fast summaries so he can spend more time talking on the phone with friends and watching daytime television.
That's the equivalent of the student saying he's so smart that he doesn't need to study or even bother reading the assigned material or attend classes. Such hubris almost always ends in failure.
George W. Bush was a famously incurious President who read little and could only be briefed with one-page summaries. But those are encyclopedias compared to the two-sentence summaries that Trump wants.
If and when America faces a true crisis, be it a natural disaster or a terrorist strike, Trump will be woefully unready and unprepared, all the more so because he has refused to nominate replacements for nearly 75 percent of top staff jobs. He thinks he can wing any crisis without preparation or staff, and that's a recipe for disaster.
As is often said about such things: this will not end well.