There is nothing so annoying as to have two people go right on talking when you're interrupting.

The line is a compact example of Twain’s comic inversion: it flips the usual complaint (being interrupted) into the interrupter’s self-centered grievance. By adopting the interrupter’s perspective, the joke exposes a small but recognizable social vice—impatience and entitlement in conversation—while also satirizing how people rationalize rude behavior. The humor depends on the clash between social norms (listening, turn-taking) and the speaker’s assumption that their interjection deserves priority. Read more broadly, it’s a miniature critique of ego in everyday manners: the world is framed as obstructing one’s own need to speak.