"Have you ever eaten bread?"/"I have. But they have not. They have never seen it."

"At least he was intelligible. The daughters spoke a language distorted by a lifetime of isolation. 'When the sisters talked to each other, it sounded like a slow, blurred cooing.'"

The old man's name was Karp Lykov, and he was an Old Believer—a member of a fundamentalist Russian Orthodox sect, worshiping in a style unchanged since the 17th century....

[In 1936] Karp; his wife, Akulina; a son named Savin, 9 years old, and Natalia, a daughter who was only 2... had retreated ever deeper into the taiga, building themselves a succession of crude dwelling places, until at last they had fetched up in this desolate spot. Two more children had been born in the wild—Dmitry in 1940 and Agafia in 1943—and neither of the youngest Lykov children had ever seen a human being who was not a member of their family. All that Agafia and Dmitry knew of the outside world they learned entirely from their parents' stories.....

The Lykov children knew there were places called cities where humans lived crammed together in tall buildings. They had heard there were countries other than Russia. But such concepts were no more than abstractions to them.

Video here.