And to add to this, it’s not always obvious that a dementia patient is having an episode if you don’t have the context and structure to recognize what they’re saying is nonsense. They can string together a perfectly coherent story and what tips the listener off is that they’re referring to someone who is long dead or an activity they couldn’t possibly have done recently.
And Trump isn’t tripped up by forgetting things, because his statements are already made up. He can just flow through and keep telling his story because it’s already all just stream of consciousness bullshit. He never needed facts in the first place because he can just say whatever he wants or divert into talking about sharks and electrified boats.