The penis drawings featured in the film are done by David Goldberg, Evan Goldberg's brother. There were close to one thousand produced, but only a handful were featured in the movie and closing credits.
Because Jonah Hill and Seth Rogen are such great friends, they were quoted as saying that when casting Evan, they weren't so much looking for a good actor, as they were "casting for a new best friend."
The pivotal penis drawings were a point of contention with the MPAA, particularly the scene with young Becca holding an image of one of them. Producer Judd Apatow said it was the subject of much legal wrangling, including how erect they could be, if veins could be shown, et cetera. However, the actress playing young Becca, Laura Marano, had a different picture to hold before they cut to the actual drawing. You can even see from the reverse that the drawing she holds appears completely different.
The word "fuck" is used one hundred eighty-six times. The movie itself is only one hundred thirteen minutes long. That averages to approximately 1.6 uses of the word per minute (eighty-four are said by Seth (Jonah Hill) alone).
According to the DVD commentary, the night that Evan (Michael Cera) describes to Becca early in the movie is "beat by beat" what Seth Rogen, Evan Goldberg, and their friend Sam Fogell did when they were in high school.
In a skit for the Special Edition DVD commentary Judd Apatow had his nine-year-old daughter with him. He asked that no one swear in front of her. Jonah Hill swore numerous times, angering Apatow. After an argument, Apatow left the commentary with his daughter.
When the two police officers (Seth Rogen and Bill Hader) ask McLovin (Christopher Mintz-Plasse) where the party is, he says, "13th and Granville". Granville Street is a busy street in Vancouver, British Columbia, where Rogen and Goldberg grew up.
On Eminem's eighth studio album, "The Marshall Mathers LP 2", "Brainless" samples the portion of the film when the clerk from the liquor store says his name in correlation to the white person who robbed the store.
Evan Goldberg had an incident involving excess drinking and stripping down in a bathroom at LA's Canter's Deli, and Rogen first heard about it when "coincidentally Joe and Anthony Russo were in Canter's and we overheard these two guys saying 'there's this naked guy drunk and passed out in the bathroom upstairs.'"
Jonah Hill wasn't keen on Mintz-Plasse after their first audition together as he felt the newcomer kept "stepping all over his lines." They pulled Hill aside, played him back the tape, and asked him to show them a single instance -- he couldn't as Mintz-Plasse was instead helping boost Hill's delivery and performance. Hill claims it was because his character wasn't supposed to like Mintz-Plasse's, but everyone calls him on it. "That's great guys, I thought we were all friends."
The scene where Evan (Cera) accidentally winds up in the room with guys doing cocaine is actually based on a real incident from Rogen and Goldberg's younger days. They attended a party when they were fourteen meant to say goodbye to a local standup comic who was moving, and Rogen's mom took them. "Everyone started doing blow," says Rogen, and Goldberg adds that "the house was owned by a midget and a bodybuilder who were a couple." "And there was a pig."
In the scene where Seth (Jonah Hill) and Evan (Michael Cera) are waiting for Fogell (Christopher Mintz-Plasse) to buy the alcohol for the party, Seth says "this plan's been fucked since Jump Street". Jonah Hill later starred in 21 Jump Street (2012) and 22 Jump Street (2014).
They were concerned early on that Michael Cera "wasn't doing anything" with the character and wondered if he needed more energy or ,if it would "read" on camera. "We had to get a thirty foot screen for video village so we could see what he's doing." His subtle comedic stylings quickly made themselves known.
Jonah Hill initially read for a smaller part despite suggesting he was perfect for Seth, the character he eventually went on to play. "How frustrated were you at that moment?" asks Apatow. "I just felt that you guys were stupid," replied Hill.
One of two Jonah Hill movies that featured breakout roles for future Best Actress Oscar winners (Emma Stone - La La Land (2016), and Brie Larsen - Room (2015)). The other film starring Hill and Larson is 21 Jump Street (2012).
The d*ck-drawing scene required "enormous legal complications" getting it to the screen. Every single drawing had to be approved individually by the studio's legal department "and we would get notes back saying 'too big, too veiny.'"
The scene in which Evan (Michael Cera) is forced to sing "These Eyes" at the adult party is strikingly similar to the scene in Dead Poets Society (1989), when Knox (Josh Charles) attends the high school party. (1) Evan and Knox are mistaken for someone's brother, who they are not. (2) Both are pressured into something by drunk partiers: Evan to sing and Knox to take a shot. (3) Both are outsiders at the parties. (4) Both parties erupt into fistfights after the cases of mistaken identity.