Wiktionary
prep.phr. (context idiomatic English) especially; more than other people
Wikipedia
Of All People is a Canadian biographical television series which aired on CBC Television from 1972 to 1974.
Usage examples of "of all people".
Mike had returned from some official business or other with Don Nasi and, of all people, Harry Lefferts.
For an instant I was sick with despair, for I knew that no ship could leave that roof unseen while anyone was abroad in the garden beneath, and Ras Thavas least of all people in the world.
If one of your troops loses it it's one thing but if the commander cracks all hell's out for noon, you of all people should realize that.
And that is the job that has been laid out for poor Pudd'nhead Wilson, of all people in the world!
Julius made problems seem easy and he of all people would understand why the “.
But to find Shandie, of all people, behaving like a sulky child was enough to unseat the heavens.
Nynaeve, of all people, turned to go back, but Lan laid a hand on her arm, and Jaem planted himself before the door with eyes not much warmer than Lan’.
Siuan herself had said that she should not put up with nonsense, and she surely could not afford to put up with it from Siuan, of all people.
Will work out, of course, but who would think the Sea Folk, of all people, would demand such a thing, even just in private?