Complex sentence: The show has been mentioned many times on TV's longest-running animated series "The Simpsons", usually by older characters, seemingly all of whom are devoted fans of the series, and under the impression that Matlock himself is a real person.
Split into simpler sentences: The show has been mentioned many times on TV's longest-running animated series "The Simpsons". Usually by older characters, seemingly all of whom are devoted fans of the series, and under the impression that Matlock himself is a real person.