It was shipped to theatres under the name "Sugar and Spice".
When Jenna is flipping through her mail just after waking up as a 30 year-old, one of the letters is from Sparkle.
Originally Young Matt was to be played by Jack Salvatore Jr.. Test audiences reacted negatively towards him and the girl originally playing Young Jenna (Shana Dowdeswell), so the parts were re-cast and the scenes were shot again.
The Poise article that Jenna is reading at 13 ("Thirty, Flirty & Thriving"), features the apartment that she later lives in at 30.
The blindfold Jenna is wearing when she is 13 is made out of the same material/pattern as the eye cover she is wearing when she wakes up when she is 30. The blindfold and eye cover were both designed by Cris Notti, an accessories designer based out of Los Angeles.
In Australia, the title was changed to "Suddenly 30" because distributors thought audiences would misunderstand the original title.
The scenes on Jenna's 13th birthday were shot twice with two different wardrobes. In the movie trailer young Jenna is wearing a multicolored top and has her hair down but in the movie she is wearing a blue top and her hair is up.
Jenna's birth date is 26 May 1974.
When Jenna hides in the closet at her thirteenth birthday party, pictures of her growing up can be seen on the back on the door. These pictures are actually of Christa B. Allen, the actress who plays thirteen-year-old Jenna.
When Jenna confronts Matt as he is dressing for the wedding, a book with the title "Time's Arrow" can be seen on the shelf beside her. The book is a novel by Martin Amis, about a man who experiences his life in reverse: the book opens as he becomes conscious as a very old man near death, and proceeds backwards through his life, ending when he is a small child.
As "Editor-in-Chief Richard Kneeland," Andy Serkis announces, "I also strongly suggest we take apart our FOB, overhaul the BOB..." In the magazine publishing industry, these acronyms stand for "Front of Book" and "Back of Book" and refer to the short articles placed at the front and back of the magazine.
In the scene right before Jenna tears down the Sparkle magazines from the magazine rack, you see her pass Matt on the street, with neither of them noticing. Even though you cannot see his face, it is obvious it is him because he is carrying a camera and is wearing the same outfit that he was wearing in the scene with Lucy beforehand. This could have backed up the fact that he and Jenna are so close, yet so far away.
Young Jenna puts her dream house that young Matt makes for her on top of the board game 'Battleship.' Later, adult Jenna asks to play Battleship at her boyfriend's house.