Claim: In the book, Pebble in the Sky, a retired tailor is transported tens of thousands of years into the future, finding himself in a place he does not recognize where people speak a language he does not recognize, and he is mistaken as mentally deficient by a couple who take him in and offer him for an experimental prcedure to increase his mental abilities.
Evidence: The book begins with a retired tailor from the mid-20th century, who is accidentally pitched forward into the future. While walking down the street in Chicago, Joseph Schwartz, a retired tailor, is the unwitting victim of a nearby nuclear laboratory accident, by means of which he is instantaneously transported tens of thousands of years into the future (50,000 years, by one character's estimate, a figure later retconned by future Asimov works as a "mistake"). He finds himself in a place he does not recognize, and due to apparent changes in the spoken language that far into the future, he is unable to communicate with anyone. He wanders into a farm, and is taken in by the couple that lives there. They mistake him for a mentally deficient person, and they secretly offer him as a subject for an experimental procedure to increase his mental abilities.