They're talented, successful and very influential in whichever field they're working.
But somehow, somewhere, they begin saying whatever comes into their minds, and their soundbites are the stuff of great swathes of the media.
One such person surely has to be German fashion designer Karl Lagerfeld.
Karl Lagerfeld (screenshot from Reuters report)
The 78-year-old scores on all three criteria, talent, success and influence.
There's no questioning his gift for creating posh frocks and the like, he heads a major fashion house, Chanel, and he can make a model's catwalk career take off, just as he did with Baptiste Giabiconi.
Sadly he's also given to pontificating on just about anything that strikes his fancy.
So when the free daily newspaper Metro made him guest editor for Tuesday's edition, Lagerfeld was given a platform not only to determine the design and contents for one day, but also to come up with some real corkers as he was asked questions on a range of issues during an interview.
Barack Obama deserves to be re-elected as far as Lagerfeld is concerned, but mainly because of his wife, Michelle, who has a "magical face" and without whom "he (Obama) would not be there."
Ah yes finger on the political pulse time from a man who admits he has never voted in his life.
There's more...of course.
The Greek economic crisis is - surprise, surprise - "a big problem as (Greeks) have a reputation of being corrupt," says Lagerfeld.
Ah that thought has never been expressed before. But wait for it, he has more.
"Greece needs to work on a cleaner image."
"Nobody wants Greece to disappear (???- not sure what he meant by that. Maybe Lagerfeld knows something the rest of us don't) but they have really disgusting habits – Italy as well.
Yep - you tell 'em Karl.
On the French presidential election; "It's not inspiring at the moment" (see video).
Well some would probably agree with him.
As far as popular music is concerned, British singer Adele has "a beautiful face and divine voice" but for Lagerfeld she's also "a little too fat."
As if the latter had anything to do with the former.
Finally - just for now (you can read the whole interview and/or watch the video if you feel so inclined) there's Queen Elizabeth II who has just marked the 60th anniversary of her accession to the throne.
Lagerfeld seems to think she's improving with age and, as far as her dress sense is concerned (and that's after all an area in which you would expect him to be able to make an informed comment) she's coming "into herself a little bit more - whatever that means."
Quite. What exactly does that mean?