The very first day of the shooting, Matt Damon and Ben Affleck started crying out of happiness, because it was a scene between Robin Williams and Stellan Skarsgård, accomplished actors, doing Damon's and Affleck's scene verbatim, and they had waited so long (four years) for this to happen.
Matt Damon and Ben Affleck found a clever way to choose the right studio for their script: the story goes that on page sixty of the script, they wrote a completely out-of-nowhere sex scene between Will and Chuckie. They took it to every major studio, and nobody even mentioned the scene. When they met with Harvey Weinstein at Miramax, he said, "I only have one really big note on the script. About page sixty, the two leads, both straight men, have a sex scene. What the hell is that?" Damon and Affleck explained that they put that scene specifically in there, to show them who actually read the script, and who didn't. As Weinstein was the only person who brought it up, Miramax was the studio chosen to produce the film.
After the 2014 death of Robin Williams, the Boston Public Garden park bench where he and Matt Damon had their conversation scene, became an impromptu memorial site for the actor with people leaving flowers, quotes and various items at the bench. A petition has been passed around to erect a statue in Williams' memory near the bench.
When Robin Williams and Matt Damon were shooting the scene on the bench in the Public Garden, in the movie, it seems like they're the only people in the park. Robin Williams being a massive star, there were, at one point, over three thousand people out there, watching that scene.
The lines in the scene when Sean talks about his late wife's farting antics were ad-libbed by Robin Williams. That is why Matt Damon was laughing so hard. If you watch the scene carefully you can notice the camera shaking a bit, possibly due to the cameraman laughing as well.
Casey Affleck ad-libbed most of his lines. This frustrated Matt Damon, Ben Affleck, and Gus Van Sant during filming, but they later admitted that Casey's improvised lines were much funnier and better than what had been originally written for him.
Initially, Producer Harvey Weinstein did not want Minnie Driver at all for the role of Skylar, feeling she wasn't cute enough for the part. Because Gus, Matt, and Ben wanted her in the movie, Weinstein ultimately relented, and Driver went on to be nominated for a Best Actress in a Supporting Role Oscar.
When Robin Williams won the Oscar for his supporting role, he sent Peer Augustinski, who dubbed his voice in German, a small replica of the Oscar statue with a note saying, "Thank you for making me famous in Germany."
When Matt Damon was in his fifth year at Harvard, he was in a playwriting class. The culmination of it was to write a one-act play, and he just started writing a movie, which, with the help of Ben Affleck, became this movie.
Gus Van Sant, at one point, asked Matt Damon and Ben Affleck to re-write the script, so that Chuckie is killed in a construction accident. Damon and Affleck protested, but reluctantly wrote the scene in. After Van Sant read it, he agreed that it was a terrible idea.
Matt Damon, a former Harvard student, originally intended to make the title character a physics prodigy. He discussed his idea with Sheldon L. Glashow, a Nobel laureate in physics, and at the time a Harvard professor. Glashow told him that the premise did not ring true to him, and suggested that the main character be a math prodigy instead. He referred Damon to his brother-in-law, Daniel Kleitman, a professor of mathematics at M.I.T., who provided advice on the story. Glashow and Kleitman are thanked in the credits.
The phone number printed on the sign for the construction company, that they are working for, is the actual phone number of a Woburn, Massachusetts construction company, that Matt Damon worked for while going to high school in Cambridge.
When Will (Matt Damon) and Sean (Robin Williams) meet for the first time in Sean's office, Will recommends that Sean read Howard Zinn's "People's History of the United States". As a boy, Matt Damon was Zinn's neighbor, and provided the voice for the CD recording of that book.
According to Matt Damon, when the project was set up at Castle Rock Entertainment, all he and Affleck had heard for the casting over them, was "Leo and Brad", referring to Leonardo DiCaprio and Brad Pitt.
After Mel Gibson dropped out of directing, Michael Mann expressed interest in directing. However, he wanted to make two major changes: He wanted Will and his friends to be car thieves, and he did not want Matt Damon for the lead role, since he was still relatively unknown then. The producers, who wanted Damon, suggested the Mann film some screentests with Damon and Ben Affleck. After Mann filmed the screentests, he went back to the producers and said he still did not want Damon in the lead, so the producers and Miramax parted ways with Mann, since the film was Damon and Affleck's project from the start.
An earlier draft of the script had Will Hunting being recruited by the government to become a cryptanalyst (based on his mathematical ability). Rob Reiner reportedly reviewed the script and advised Matt Damon and Ben Affleck to eliminate this subplot. However, there is a reference to it in the final script: the scene where Will meets with N.S.A. Agents, and explains why he doesn't want to work for them.
In his first scene, Robin Williams is standing in front of a blackboard. Behind him, are written on the blackboard in chalk, the words "Susser 1969". In 1969, Williams graduated from Redwood High School, Larkspur, and then continued at College of Marin, Kentfield just a few blocks away from the High School. He became acquainted with the Drama Department there at the College of Marin, and performed in the production "Taming of the Shrew" by William Shakespeare. Robin Williams' first stage director was the late Harvey Susser. Thus, the blackboard "code words" seem to say: "Hey, Harvey! See this! Now I'm the teacher!"
In a Boston Magazine retrospective interview, Ben Affleck mentioned that he and Matt Damon wrote the part of Sean Maguire with Morgan Freeman or Robert De Niro in mind, and he and Damon would imitate their voices when reviewing the dialogue in the script.
At a WGA seminar in 2003, William Goldman denied the persistent rumor that he was the actual writer of Good Will Hunting: "I would love to say that I wrote it. Here is the truth. In my obit it will say that I wrote it. People don't want to think those two cute guys wrote it. What happened was, they had the script. It was their script. They gave it to Rob (Reiner) to read, and there was a great deal of stuff in the script dealing with the F.B.I. trying to use Matt Damon for spy work because he was so brilliant in math. Rob said, "Get rid of it." They then sent them in to see me for a day. I met with them in New York, and all I said to them was, "Rob's right. Get rid of the F.B.I. stuff. Go with the family, go with Boston, go with all that wonderful stuff.", and they did. I think people refuse to admit it because their careers have been so far from writing, and I think it's too bad. I'll tell you who wrote a marvelous script once, Sylvester Stallone. Rocky's a marvelous script. God, read it, it's wonderful. It's just got marvelous stuff, and then he stopped suddenly, because it's easier being a movie star and making all that money, than going in your pit and writing a script. But I did not write Good Will Hunting, alas. I would not have written the "It's not your fault" scene. I'm going to assume that 148 percent of the people in this room have seen a therapist. I certainly have, for a long time. Hollywood always has this idea that it's this shrink with only one patient. I mean, that scene with Robin Williams gushing and Matt Damon and they're hugging, "It's not your fault, it's not your fault." I thought, Oh God, Freud is so agonized over this scene. But Hollywood tends to do that with therapists."
Sean's office is set up like a baseball diamond, with four chairs representing the bases, and a table in the middle, like a pitcher's mound. This is most noticeable during the Carlton Fisk homerun reenactment.
The odd and perplexing line, "I swallowed a bug", said by Morgan (Casey Affleck) in the Harvard bar scene, is a reference to the documentary "Hearts of Darkness", as well as actor Marlon Brando. The behind-the-scenes documentary tells of the making and struggles Francis Ford Coppola had during the production of Apocalypse Now (1979). In a look at one of Marlon Brando's scenes, his line is interrupted when he accidentally swallows a real bug, and states to Francis Ford Coppola off-camera, "I swallowed a bug."
The script was originally developed by Castle Rock, Rob Reiner's production company. When they didn't know what to do with it, Kevin Smith took the script to Miramax. It became the highest grossing film in Miramax history, until Chicago (2002) topped it.
The mathematical equations seen in the opening credits are part of a math technique called "Fourier Analysis" which approximates functions by sines and cosines. It's used a lot in physics and engineering.
After Matt Damon and Ben Affleck sold their script to Castle Rock, it was printed in Daily Variety that they were going to get six hundred thousand dollars for it. By using a copy of the Daily Variety, because Affleck and Damon had no credit at the time, they rented a house that was three thousand dollars a month.
To date, this is the film with the highest U.S. box-office gross with Kevin Smith's name attached to it. All his own films, that he has written and directed, have not grossed more than thirty-five million dollars at the U.S. box-office.
In the scene on the park bench, Robin Williams gives an example of love that Will hasn't experienced as "going to hell and back for it." In his next movie, What Dreams May Come (1998), Williams does just that for his love, played by Annabella Sciorra, after she commits suicide.
On The Graham Norton Show (2007), Harvey Weinstein revealed that when he first read the script there was a scene were Sean and Gerald give each other oral sex. Weinstein questioned Matt Damon and Ben Affleck about this, and they responded that it was written as a gag to make sure he actually read the script.
While a guest on Late Show with David Letterman (1993), Robin Williams joked about his experience after winning an Oscar for his role in this film: "It's amazing. When you win the Academy Award, you have, like, about a about a week where everyone's like, 'Hey, Good Will Hunting--way to go! Good Will Hunting, Academy Award, way to go!' And two weeks later, it's like, "Hey, Mork!' How are ya?'"
While looking over some of Will's work, Lambeau remarks, "I see you used Maclaurin here," referring to a mathematical representation called the Maclaurin series. Coincidentally, McLaurin was Robin Williams' middle name.
After Matt Damon and Ben Affleck removed the N.S.A. stuff from the script, Castle Rock, by that time, owning the rights to the script, gave them time to go out and find somebody who will buy their version of the movie, meaning a director. But there was a price tag: Castle Rock wanted to get their money back. So if they couldn't find anybody to buy it, when it came back to Castle Rock, they were not going to be the stars anymore.
First film in Kevin Smith's and Scott Mosier's filmography to receive Oscar recognition. Though they weren't nominated themselves, they were still instrumental in getting the films production even happening. Kevin Smith was friends with Ben Affleck after his casting in Mallrats (1996), then cast him as the lead in Chasing Amy (1997). Following Matt Damon's cameo role, along with Brian O'Halloran as television producers, was after Affleck introduced the pair, which led to them giving Smith the screenplay, ultimately landing with Harvey Weinstien of Miramax.
In an interview, between Matt Damon and Kevin Smith at IMDb's 2016 San Diego Comic Con, Matt mentions that Kevin was instrumental in the movie being made. As it was Kevin that brought the script directly to Harvey Weinstein, when the other studios were not showing interest.
Many years after the fact, Ben Affleck admitted to having had concerns after the film's success that he would just be regarded as "Matt Damon's stupid friend. Yes, that stayed with me for a while.", from an appearance on The Graham Norton Show (2007).
Ben Affleck's father and stepmother worked as janitors at Harvard University. In 2000, Ben Affleck and Matt Damon spoke at a rally at Harvard University in support of an increased living wage for all workers on campus. Ben Affleck narrates a documentary, Occupation (2002), about a sit-in organized by the Harvard Living Wage Campaign.
In the film, Skylar talks about her father having died years prior. Skylar Satenstein's father, Frank Satenstein, a television director, died in 1982, years before Skylar and Matt Damon were dating at Harvard.