What did Donald Trump do today?

He reminded everyone how much he knows about aircraft and military matters.

Iran reportedly shot down an American drone aircraft in international waters yesterday, which had the odd effect of forcing Trump to dial back his warlike rhetoric against the country. He told reporters that he assumed that the deliberate targeting and firing of missiles against the $220 million drone had been a "mistake" made by "somebody who was loose and stupid." Then, he added this clarification:

It was not — there was no man in it... We didn’t have a man or woman in the drone. We had nobody in the drone. It would have made a big difference, let me tell you.

Being unmanned is more or less the definition of drones, which are also known as UAVs (unmanned aerial vehicles).

Trump, who by his own admission knows "more about ISIS than the generals" and more about the economy than the Federal Reserve, has been reminding people at least since this January that he also knows "more about drones than everybody." He's been particularly eager to share his knowledge of aviation lately: when Boeing's 737-MAX passenger jets were grounded, he explained to them that "airplanes are becoming far too complex to fly" and that "computer scientists from MIT" should take a back seat. (In reality, jets have gotten safer and safer even as planes have gotten more complex.)

Trump has also spent a fair amount of his time recently picking out colors and paint styles for the next version of Air Force One.

Why does this matter?

• It's bad if the president talks as though he's an expert about things he doesn't know much about.

• Drones that cost $220 million and are flown in what may become war zones are things a president actually should know something about.