The idea, from an essay in The New Yorker, is that someone from 1914 arrives in the present, and talks to someone behind a curtain.
'The traveller’s queries are answered by a voice with an accent that he does not recognize (twenty-first-century American English). The woman on the other side of the curtain has an extraordinary memory. She can, without much delay, recite any passage from the Bible or Shakespeare. Her arithmetic skills are astonishing—difficult problems are solved in seconds. She is also able to speak many foreign languages, though her pronunciation is odd. Most impressive, perhaps, is her ability to describe almost any part of the Earth in great detail, as though she is viewing it from the sky. She is also proficient at connecting seemingly random concepts, and when the traveller asks her a question like “How can God be both good and omnipotent?” she can provide complex theoretical answers.'
So, the punchline: the person behind the curtain seems to have a high level of knowledge in some ways, but in fact is simply holding a smart phone.
I, myself, come from the past,
and I have to say: they're a blast.