Today, Trump tweeted that the Moon is part of Mars. He recently repeated several times that he wanted AG Barr to investigate the “oranges” of the Mueller Report. He calls people by the wrong names frequently. His lack of preparation for meetings and tendency to say things that show his lack of understanding make it seem worse.
Trump has often been seen wandering off when he gets off of Air Force One. And he frequently walks out of a signing ceremony without remembering to sign the document. People who have known him for years say they notice his mental capacity and ability to focus is diminished a great deal.