In 2011, Paul Rudd told Entertainment Weekly that he was literally not sure he ever got paid for this movie. He thinks that because the budget and the production staff were both so incredibly small, they may have just overlooked making out a check for his salary.
While a guest on Live! with Regis & Kelly in 2010, Bradley Cooper was asked which of the many actresses with whom he has co-starred was his favorite on-screen kisser. Instead of an actress, he chose Michael Ian Black, with whom he shared a love scene in this movie.
In late 2014, Netflix announced that they would shoot and air a miniseries continuation of this movie, featuring nearly all of the same actors and actresses. However, instead of being a sequel, the new miniseries would be a prequel, with the actors and actresses (most of whom were already up to a decade too old to play their teenage characters back in 2001) playing even younger versions of the same characters they portrayed in the first movie.
The shooting script included a dark comedy scene where careless counselor Andy (Paul Rudd) murdered a camper in order to cover up the many drowning or other deaths that occurred due to his negligence, but Director and co-Writer David Wain cut the scene after he gave the screenplay to his father to look at, because Wain's father said Wain would be disowned by him if he put something that horrible in the movie.
During the scene where Beth (Janeane Garofalo) is announcing which campers need to put their trunks out for an early bus, Janeane Garofalo improvised most of the names. You can hear her call for "David Ben-Gurion", who was the first Prime Minister of Israel. Another name she calls out is "Rabbi Menachem Schneerson"; Menachem Mendel Schneerson was perhaps the best-known twentieth century leader of the Chabad Lubavich Hassids, a movement within Ultra-Orthodox Judaism. For many of the other names, she was reading from Camp Towanda's five-year-club plaque.
According to the Entertainment Weekly article from the July 1, 2011 issue, Hank Azaria was a camper at Camp Towanda from age six to fifteen. Janeane Garofalo (his co-star from Mystery Men (1999)) called him after she saw his name on a bunk plaque. Garofalo then gave him a shout out during a scene where she ad-libs a roll call of campers, using the name Jessica Azaria.
In a July 2015 Entertainment Weekly interview, David Wain said that the ordeal that Victor underwent while trying to get back from leading a canoe trip to "make out" with Abby, was based on an experience he had while he was a camp counselor: "I had just turned sixteen. I was assigned to drive a group of campers to an overnight camping trip and leave the next morning with another counselor and head back to camp. But, I had just met this girl at the camp and I was so excited to see her that I decided, 'No, I'm going to leave late at night and race back to camp', even though I barely knew how to drive. So I cranked up the tunes, pedal to the metal, and I was driving through pitch black, winding unpaved roads as fast as I could, in hopes of making out with this girl, and about two miles away from the campsite, but still in the middle of this state park, I smashed hard into a tree. I lodged the fender deep into the tire, rendering the van utterly undriveable, and was stuck in the middle of the woods. I had no idea how to get back, I couldn't see my hand in front of me, but luckily I did end up wandering back to find the campsite with the kids and the counselor and they were like, 'What the hell is wrong with you?' After that, they initiated a policy that junior counselors weren't allowed to drive vehicles at camp. I eventually did get to make out with the girl."
According to co-Writer and Director David Wain and co-Writer Michael Showalter, rejected titles for the movie include: -American Love Bunk -American Nametags in Underwear -American Wedgie -Ankle Bites: The Movie -Associate Professor Neumann Goes to Camp -Big American Love Wedgie -Blue Balls -Boner Camp -Boners and Clits -Boyside/Girlside -Bring a Change of Underwear -Buddy Check -Bug Juice '81 -Bunk Bed America -Bunk You -Butt Camp -Cabin Pressure -Camp Fire -Camp Homesucks -Camp Masturbate Each Other -Counselors and Cancers -Damp Vagina Camp -Dew Dew -Fresh Grass -General Swim -Goin' to Third -Hot American Wedgie -Hot Kids in Shorts -Hot Wedgie Days -Internment Camp -The Maine Squeeze -Morning Wood -Postcards From the Cot -Sex, Flies, and a Videotape of a Kid Masturbating -Slow Dance Boner -S'more, Don't Stop -Suck My Big Hard Camp -Taco Meat Drips on Nipples 2 -Teenage Sex Fields -Tits and Taco Day -Waterfront Blues -Welcome Back Cot -Wet Hot Beds Marguerite Moreau claims Paul Rudd was using "Bring a Change of Underwear" as the title for an autobiography.
While Coop (Michael Showalter) is listing for Katie (Marguerite Moreau) all the reasons he loves her, one of the things he says is "I love it that sometimes for no reason you're late for shul." "Shul" is a Yiddish term that refers (sometimes colloquially) to a Jewish house of worship (also known as a synagogue or a temple).
Paul Rudd, Elizabeth Banks, Ken Marino, A.D. Miles, and Joe Lo Truglio, appeared in Role Models (2008), also directed by David Wain. Both films also contained a character named Beth and include the eponymous KISS song, "Beth".
The filmmakers have stated that the reason the talent show production of "Day by Day" is booed is often misunderstood. The audience boos in spite of it being particularly well-produced, but it is commonly assumed to be because it ends with a cross being lit up and the camp is mostly Jewish.
The trivia item below may give away important plot points.
There was supposed to be a moment during the talent show in which young camper Aaron ( Gideon Jacobs ) kisses camp counselor Gail ( Molly Shannon ) after she publicly denies her ex-husband Ron. However, the crew and Jacobs' parents could tell that he, being only 12 at the time, was very uncomfortable with this action, so they changed the blocking to him simply brushing Gail's hair behind her ear. Years later, Jacobs stated that several people have told him that his small gesture was one of their favorite little moments of the film.