Inappropriate speech is a common symptom of Alzheimer's dementia.

[ChicagoRonin]

11. It's also common among the overprivileged

Not to counter the extremely compelling observations that something is not right upstairs with Herr Trump, but I've also encountered similar behavior among people who are, for lack of a better word, really spoiled.

If you're and average and ordinary person, and if especially lucky circumstances have not come your way, your interactions with other people involve a lot of navigation and negotiation. You learn through trial and error that being inconsiderate, not being mindful of what you say, and not communicating clearly will not get you what you want. Sure, some bullies and louts manage to secure jobs, spouses, etc. but mostly you end up socially isolated or rejected.

However, being blessed with material wealth (like Trump) and being constantly surrounded by family or friends who forgive your every transgression means you never master the above social skills. It's because you don't have to.

Not to stereotype all rich people, but in college it was always the wealthier kids I met who acted like brats towards RAs, trashed dorm room public areas with impunity, or ran up massive credit card debt (which their parents covered). And they never, ever, ever seemed to show any remorse for it.