Of-all-people meaning

She didn't understand why he'd chosen her of all people.

I mean, you two, of all people.

"You of all people could probably help me about now," he said.

You of all people understand how things should work.

As the 18th century progressed the use of tea in England rapidly increased, and by the close of the century the rate of consumption exceeded an average of 2 lb per person per annum, a rate in excess of that of to-day of all people except those of Mongol and Anglo-Saxon origin.