The duo became the first members of the original "Simpsons" writing staff and worked on the thirteen episodes of the series' first season (1989–90). While watching the first episode of the show, "Simpsons Roasting on an Open Fire", premiering on television in December 1989, Jean opined to himself that the series was the greatest project he had been involved with and desired to continue working on it for the rest of his professional career. What he enjoyed most about "The Simpsons" at the time was something he recognized from Brooks' previous work: although the show was largely based on humor, it had depth and warmth.