People
"All right," said Ford, "I'll try to explain. How long have we known each other?"
— Douglas Adams

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Ford agrees to explain, then begins by asking how long he and the other person have known each other. The question turns an explanation toward their shared acquaintance. It creates an expectant pause, leaving the reader waiting to discover why that history matters.
Context reviewed