13 Going on 30

13 Going On 30 is a Romantic Comedy movie about a girl named Jenna Rink (Jennifer Garner) who is 13 and suffers from the ageless drama of 13-year-old girls: she doesn't have enough boobs, she doesn't have enough cool clothes, she doesn't have a beautiful and popular boyfriend, and she definitely doesn't have friends among the In Crowd.

As a solution to this, she wishes to become older and successful and beautiful and popular and pretty much everything else. So, with a little help from a magic dust, she ages seventeen years in a blink, and wakes up as powerful magazine editor, whose best friend is Lucy Wyman, aka Tom-Tom (Judy Greer) the old queen bee at her school.

The only problem is: she doesn't remember a thing of how she passed the past years. Matt (Mark Ruffalo), a nerd who was her only friend at high school, helps her to find herself; but what if she does not like how she turned out to be?

For the trope that this movie used to name, see Overnight Age-Up.

Tropes used in 13 Going on 30 include:

Alpha Bitch: Tom-Tom (a.k.a. Lucy) in her high school days.
Ambition Is Evil: So, you want to be thirty and have money and power and boobs? Absurd. The only way you'll ever have all that is if you became a Class A Bitch.
Anguished Declaration of Love: Jenna to Matt, right before his wedding.
Brainy Brunette: Jenna, of course. Yes, she may have turned out to be a 30-year-old bitch, but she certainly isn't dumb.
Blondes Are Evil: Tom-Tom, who is very blonde in the beginning of the movie.
Character Development: Jenna realizes that maybe there's more to life than money and success. Something more along the lines of Becoming A Better Person.
Corrupt the Cutie: In this case, Jenna kind of corrupts herself, but...
Dance Line: Jenna does this during the "Thriller" dance part.
Did Not Do the Research: The key songs in the movie are "Jessie's Girl," "Love Is A Battlefield" and "Thriller" -- hits in 1981, 1983 and 1984 respectively, which don't really seem credible for a 13-year-old girl in 1987 (which she would have to be, since the film was released in 2004) to have at the top of her fave raves list -- and someone on the production must have known this, hence Jenna bursting into the much more plausible "Everybody Have Fun Tonight" by Wang Chung (from 1986).
Doting Parent
Embarrassing Nickname: Tom-Tom. I mean, Tom-Tom?
- Not that Jenna's is any better -- "Sweetbottom"? (Mind you, many men would agree it fits considering she's played by Jennifer Garner.)
Emotional Torque: The always present Aaaaaaaw Sound, mostly. Specially at the end, when the Loving Couple finally get together.
"Falling in Love" Montage
Family Versus Career: Jenna has to choose: She gets True Love, or she gets a good job and a lot of money. There's more to the plot than that, but these are pretty much the basics of it.
Fashion Magazine: "Poise" magazine.
Fish Out of Temporal Water: Jenna goes from being a teen in The Eighties to being an adult during the Turn of the Millennium. The movie ignores many of the problems (and humor) which might result from the Time Travel aspect of the plot. Is Jenna going around as a 30-year-old high-powered magazine editor in 2004 thinking the Soviet Union still exists or that Michael Jackson is still black? Who knows, it's never brought up. However, a few jokes are brought up: she doesn't initially know what a cell phone ringing is, and she thinks Eminem is the candy brand.
Future Me Scares Me
Girl Next Door: Jenna and Matt grew up next door to each other.
Girl Posse: The Six Chicks
Growing Up Sucks
Happily Ever After: What did you expect?
Hey, It's That Guy!: Jenna's boss is frikkin' Gollum!
- Younger Matt was Mac
  - Older Matt is Bruce Banner.
Home, Sweet Home
High School: The part between times that she doesn't remember, that is.
High School Sweethearts: Jenna and Matt, obviously.
Horrible Judge of Character: Jenna concerning Lucy.
Just Friends: Jenna and Matt.
Market-Based Title: For no apparent reason, the movie was released in Australia and Brazil as Suddenly 30.
The Mole: Jenna had been feeding a rival fashion magazine with ideas for articles that her magazine had been coming up with.
Name's the Same: Jenna and Matty
Overnight Age-Up
Popular History: The version of 1987 in which 13-year-old Jenna lives like a modern-day '80s-themed party.
Race For Your Love: Jenna rushing to catch Matt at his wedding.
Separated At Birth Casting: Christa Allen as Young Jenna. Jennifer Garner says that she looks identical to her when she was that age and the two were cast in similar roles in Ghosts Of Girlfriends Past.
Sleep Mask: Used by Jenna when she wakes up as adult.
Stepford Smiler: Jenna, when she wakes up 30, finds she is not the nice young girl she used to be.
The Reveal: Done twice because the first-time viewers in the audience wouldn't know the significance of the letter from the rival Sparkle Magazine that turns up in her mail in the first reveal either.
Or Was It a Dream?
Reset Button
Ridiculously Successful Future Self
True Love's Kiss: Again, what did you expect?
Victorious Childhood Friend
X Meets Y: Big meets Regarding Henry with liberal sprinkling of Peggy Sue Got Married in reverse.
You Can Leave Your Hat On: Jenna's boyfriend in a very-not-sexy scene.
- To "Ice Ice, Baby" by Vanilla Ice, yet!
What Happened to the Mouse?: To Matt's fiance
When She Smiles: The late night walk between Jenna and Matt.