During an interview on The Mike Douglas Show (1961), Herman Raucher said that after the novel and movie were released, several women wrote letters to him claiming to be Dorothy. One of the letters was indeed from the real Dorothy, who wanted to know if she had psychologically damaged Raucher, and also informed him that had been happily remarried and was now a grandmother. It was the last time that Raucher, by that time married with children, heard from Dorothy.
Though author Herman Raucher admits to moving the order of certain events around and interchanging some dialogue, the movie is (according to those involved) an accurate depiction of events in Raucher's life in the summer of 1942 on Nantucket Island; he didn't even change anyone's name. He began writing the screenplay as a tribute to his friend Oscy, who'd been killed in the Korean War, but midway through writing it Raucher realized that he wanted to make it a story about Dorothy, who he had in fact neither seen nor heard from since their last night together as depicted in the movie. Raucher admits that in all the time he knew her, he never bothered to ask her what her last name was.
In 2002 TCPalms interview, Herman Raucher mentions that this film gave birth to the book "Summer of '42." Herman Raucher revealed that this movie was written first. Not the book. When this film was in post-production, someone told him to write the book about Summer of '42 to help publicize the picture. So Herman Raucher wrote the book in about 3 or 4 weeks.
Summer of '42 was originally banned in Ireland when first released in 1971 because the hermie character buys contraceptives from a drug store whilst under aged (contraception was banned in Ireland in the 1970s). The movie was eventually released theatrically in Ireland in 1979 (uncut).
Although Dorothy wished Hermie only good things in her letter to him, still Hermie ended up facing several depressing incidents after she left him. Herman Raucher was severely depressed about not hearing from Dorothy after she left him. Hermie's sister's fiancee died in 1944. Hermie's father passed away when he was 20. Hermie's best friend Oscy died on Hermie's 24th birthday. Since the death of Oscy, Hermie was never able to celebrate a birthday again.
In this film, there is no name for the druggist played by Lou Frizzell. But in the book "Summer of '42", it is revealed that the name of the druggist is Mr. Sanders. In the book "Summer of '42", it is revealed that the name of the druggist is Mr. Sanders. In the trailer for the film, Oscy', while looking at pictures in the anatomy book and discussing taking those kinds of pictures and how they would process them says to Hermie: "Come on, what drug stores would develop 'em? If we took film like that to Old Man Sanders we'd be put in reform school."
With the exception of the beginning credits and the end, Michel Legrand used his music only around the scenes that involved Dorothy and the scenes that showed Hermie's romantic feelings towards Dorothy.
Since the audience is exploring Dorothy in the film through Herman Raucher's point of view, we don't know how much Dorothy in the film differs from the real Dorothy. Jennifer O'Neill played Dorothy in this film based on how Herman Raucher saw the real Dorothy through his point of view.
Some critics of this film questions the veracity of this film although the film was based on the incident that claimed to be happened in the summer of 1942. One of them is this film and the book "Summer of '42" claim that Hermie and Oscy saw the film "Now voyager" during Summer of 1942. But the initial release of Now Voyager was only in 22nd October of 1942 (in New York City) and the official release date of the film throughout USA was in October 31, 1942.
The trivia items below may give away important plot points.
In 2002 TCPalms Interview, Herman Raucher said that the postmark of the real Dorothy's 1971 letter was Canton, Ohio. Herman also said that the real Dorothy was worried about what she had done to him and his psyche. Herman also added this "And no one has ever thought about that. Everybody thought, 'Oh, that's interesting. The kid grew up.' But it was a traumatic event." And her last sentence was, 'The ghosts of that night 30 years ago are better left undisturbed.'
After Dorothy left Herman Raucher in real life, Herman had a strange reaction where he tried to date every girl he could find whose name was Dorothy. This was mentioned in 2002 TCPalm extended Interview with Herman Raucher.
There are differences between the real life incident that happened during that night and the incident we see in the film. In real life, the real Dorothy was "heavily" drinking and the song that played on Phonograph record was That Old Feeling. The real Dorothy kept calling Hermie "Pete" thinking that Hermie was her husband while they both were in bed. Although the real Dorothy kept calling Hermie "Pete", still she told Hermie "Good Night, Hermie" before Hermie left her house. In the film, it is implied that Dorothy "may" have been drinking. But when Dorothy appears to Hermie in the film, visually there is no indication of her being drunk at all. The film focuses on the impact of the shocking news on Dorothy. Instead of using the song "That Old Feeling", Michel Legrand composed a new score for the dancing scene. In the film, Dorothy turns to Hermie for comfort. There is no indication in the film that Dorothy is imagining Hermie as her husband Pete. In the film, Dorothy is completely aware of what is going on. Unlike the real Dorothy who left Hermie in real life, the changes that were made in the film makes it uncertain that Dorothy in the film will leave Hermie at the end.
The telegram on Dorothy's coffee table at the end of the movie lists her married name as Walker. It also gives her address as 210 North Corry Street in Bangor, Maine, and reveals that her husband was a member of the U.S. Army Air Corps and was killed in action over France.
Although the real Dorothy wrote to Herman that she will remember him in her 1942 letter, still she contacted Herman again only after the release of this film in 1971. After Dorothy's 1971 letter to Herman, Herman never heard from Dorothy again. Herman wanted to contact Dorothy. But he didn't know where to write to her, because Dorothy didn't reveal her address in her 1971 letter to Herman.
In a 2002 Scripps Treasure Coast Publishing interview, Herman Raucher lamented never hearing from Dorothy again after her letter to Herman Raucher in 1971 and expressed his hope that she was still alive.
The relationship between the real Dorothy and Herman Raucher was longer than what we see in the film. Herman Raucher first helped Dorothy carry her groceries when her husband was there. After her husband left for war, Dorothy became alone and Herman would bump into her. Herman helped her again by carrying groceries and later putting boxes in the attic like we see in the film.
For this film, Raucher admitted about moving the order of certain events around and interchanging some dialogue. There are several notable differences between Dorothy in the book and Dorothy in the film. Unlike Dorothy in the book, Dorothy in the film is far more kind, considerate, and loving. For example, one of the changes is where Hermie's tongue gets hurt by the coffee. Both in the film and in the book, Dorothy helps Hermie by providing ice when Hermie's tongue gets hurt by the hot coffee. Unlike Dorothy in the book, Dorothy in the film repeatedly apologizes to Hermie for the coffee being too hot and makes sure that he is doing fine. In the film, Dorothy moves on to her work and also to a conversation "only" after she makes sure that Hermie's tongue is feeling better. But in the book, there is no indication of an apology from Dorothy. In the book, when Hermie was "able" to look up to see what Dorothy was doing after getting relief from the ice cubes, he saw her sitting opposite to him and she was already eating one of the doughnuts and she was talking about her old 1934 stove.