Peter Sellers did not give a pony to his son Michael as shown in the film. He gave it to his younger daughter by Britt Ekland several years later. The change was made in order to compress events for dramatic purposes. According to the screenwriter, the horse disappeared after a couple of weeks, and when his daughter wanted to know where it was, he replied that he had given it to Princess Margaret.
Not only were scenes with Peter Sellers' fourth wife, Lynne Frederick, cut from the final print, but no direct mention of his third wife or fiancé Liza Minnelli is made. Their short engagement ended, when she pulled off his toupée as a joke.
Rob Brydon played Dustin Hoffman in a deleted scene, which took place at the 1980 Academy Awards and involved Sellers losing the Oscar for Best Actor (for his performance in Being There (1979)) to Hoffman (for his performance in Kramer vs. Kramer (1979)), During his acceptance speech Hoffman declared, "I refuse to believe that I beat Peter Sellers". Though the Academy Awards scene was deleted, the framing scene of Sellers watching it on television, is still in the movie. It has merely been re-edited, so what's playing on the television has been changed to the scene from Being There (1979) that he filmed. The look on Sellers' face as he watches, was originally his expression while rewinding the tape of Hoffman saying, "I beat Peter Sellers" and playing it over and over again. Stephen Hopkins says on the DVD commentary, that the scene was altered because his dramatic point got lost in the exposition of showing Sellers' losing the Oscar.
In the original concept, the screenwriters wanted Peter Sellers to comment on himself through his own characters as they sat around the War Room set from Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb (1964). The idea was dropped, because it would have been prohibitively expensive in royalties. As an alternative, they decided to have Sellers speak about himself through the characters, from family and colleagues.
Won the most Emmys for a made-for-television movie without winning for the Outstanding Made for Television Movie award. It won nine Emmy Awards for Outstanding Cinematography for a Miniseries or Movie, Outstanding Hairstyling for a Miniseries, Movie or a Special, Outstanding Prosthetic Makeup for a Series, Miniseries, Movie or a Special, Outstanding Single-Camera Picture Editing for a Miniseries or a Movie, Outstanding Sound Editing for a Miniseries, Movie or a Special, Outstanding Special Visual Effects for a Miniseries, Movie or a Special, Outstanding Writing for a Miniseries, Movie or a Dramatic Special, Outstanding Directing for a Miniseries, Movie or a Dramatic Special and Outstanding Lead Actor in a Miniseries or a Movie--Geoffrey Rush.
In one shot of a cinema marquee, a poster for The Blockhouse (1973) is visible, advertising Sellers as one of "Eight men trapped in a bunker." Below Sellers' name appear those of six of Sellers' seven co-stars. The missing name? Peter Vaughan, who plays Sellers' father in this film.
The meeting between Peter Sellers and Stanley Kubrick, in the hotel hallway, is an homage to The Shining (1980), one of Kubrick's most iconic films, as it has the same tracking shots, color palette and camera angles of the famous tricycle sequence through the hallways of the Overlook Hotel.
Although the scenes featuring Emilia Fox's performance as Peter Sellers' fourth wife Lynne Frederick were left out of the final cut, Fox is still visible in the background of the scene showing the filming of a scene from Being There (1979). She is the blonde woman standing behind the cameraman and crew behind Peter Sellers (Geoffrey Rush). In a deleted scene on the DVD, there is a continuation of this scene. After the take is over, Lynne tries to talk to Sellers, but he remains in character as the simpleton Chance.
The cartoon character of Peter Sellers in the opening animated title sequence went through over forty changes until the final character was settled upon. The character was based on Geoffrey Rush's performance/performances of Sellers and was created by Irish animator Paul Donnellon of VooDooDog.
The photo behind the Casting Agent, who's hiring him for Big Time Operators (1957), has a picture of her and Cesar Romero behind her. Romero did several films in Britain in the early 1950s. Also recognizable in a wall photo, is Margaret Rutherford.
Michael Sellers had a turbulent relationship with his father, but he always tried to defend his legacy. When the film was released, Michael scolded director Stephen Hopkins. He didn't enjoy the way his father was portrayed as clinically insane in the book, upon which the film is based. He described the book as "four hundred pages of rubbish." This forced Hopkins to go to Cannes in an attempt to appease Michael.
Although it's not mentioned, Peter Sellers was working with Kim Novak and Dean Martin on Billy Wilder's Kiss Me, Stupid (1964) when he was stricken with his first heart attack. Wilder replaced him with Ray Walston. The movie was such a big flop, that United Artists did not want to release it directly itself. It was picked up by United Artists' subsidiary, Lopert Films, which usually dealt with foreign films of limited or strictly art-house appeal.
When Peter Sellers is in the car having sex with Sophia Loren's body double, the song being played is "Goodness Gracious Me". This particular song was performed as a duet between the real-life Sellers and Loren, and was a hit in late 1960 throughout Europe.