The song's signature music video famously features the band running nude on the streets of Los Angeles.

[2] Blink-182, consisting of bassist Mark Hoppus, guitarist Tom DeLonge, and drummer Scott Raynor, formed in the early 1990s, and by the end of the decade, had reached commercial success with their second album, 1997's Dude Ranch.

Its lead single, "Dammit (Growing Up)", became one of the most-played U.S. modern rock hits of 1998,[3] sending its parent album to a gold certification and bringing the members newfound notoriety and wealth.

[7] Earlier that year, Raynor had been expelled from the group and replaced with percussionist Travis Barker, previously of the ska-punk act the Aquabats.

The story in the song is not strictly autobiographical, but its central theme resonated with Hoppus, who spent his twenties by his own admission "acting like a jackass teenager".

Each chorus is lyrically distinct, which was one of Hoppus's original goals; he felt this approach kept the song interesting and advanced the story in a creative way.

Finn was suggested by major label MCA as an option for producing Enema of the State; the band got along with him immediately, and continued to work with him on their future projects.

The drums on Enema of the State were tracked at Mad Hatter Studios in North Hollywood, a space once owned by jazz musician Chick Corea.

Hoppus remembered that Finn was meticulous in recording the kit, spending hours on microphone placement, as well as picking compressors and at which rate they would run.

While recording, Hoppus liked how the arpeggiated chord progression continued over the rhythm guitar line in the last chorus, and wished to extend its length to highlight this element.

[18] Lord-Alge had previously remixed the Dude Ranch singles "Dammit" and "Josie" for radio, and would work with the group frequently in the future.

[4] The working title for the song was "Peter Pan Complex",[19] referencing the popular psychology concept of an adult who is socially immature.

Previously, the label had appended parentheses to its two stateside singles from Dude Ranch: "Dammit (Growing Up)" and "Josie (Everything's Gonna Be Fine)".

Aside from featuring Blink's most recognizable riff this side of "Dammit", the song is an honest, relatable assessment of what it feels like to be dragged kicking and screaming into adulthood.

Carrie Bell at Billboard deemed the song a "peppy punk anthem"[8] while Spin columnist Jeffery Rotter called it an "ideal tonic for back-to-school nausea.

Club, complimented its catchy sensibility, remarking, "you'll never go broke creating an anthem for immature post-adolescents, even working within a well-worn genre.

Jon Blisten of Beats Per Minute deemed it one of the record's "finest songs," calling it a "twisted, self-depreciating examination of man-children.

"[36] In 2014, Chris Payne of Billboard called it "the quintessential Blink manifesto — the story of a twenty-something who still acts like a child.

"[37] The website Consequence of Sound, in a 2015 top 10 of the band's best songs, ranked it as number six, with writer Collin Brennan observing that its title is "the question underpinning the entire Blink ethos".

", directed by Marcos Siega, features the band running in the nude through the streets of Los Angeles, as well as through commercials and daily news programs.

Siega and PeQueen developed the idea from the band's onstage antics; Barker would often strip down to his boxers due to heat, while Hoppus would sometimes disrobe entirely, with only his bass guitar covering his genitals.

[42] The clip features cameo appearances by porn star Janine Lindemulder, the model featured on the cover of Enema of the State,[43] and television personalities John Henson and Jim Rome as well as anchors from Los Angeles station KTLA as the band ran through the sets of their respective shows (Talk Soup, The Last Word with Jim Rome, and KTLA 5 News).

Several of the group's contemporaries ranked the song among the genre's most influential, including Jack Barakat of All Time Low, Pierre Bouvier and Chuck Comeau from Simple Plan, and Tyson Ritter of the All-American Rejects.

[54] Rolling Stone's Nicole Frehsée wrote that, "For a new generation of emo fans and bands, Blink's irreverent, upbeat take on punk rock with hits like "What's My Age Again?"

[56] The Hollywood Reporter's Mischa Pearlman, in a review a 2013 concert by the group, wrote that the song "visibly infects every member of the audience.

It's been imitated thousands of times since, but nothing's come close to this..."[58] By the late 2000s, club promoters in the U.K. created nights based around lasting appreciation of the pop punk genre, including one named after "What's My Age Again?

[60] Mackey praised the lyrics by saying, "it's very much this portrait of this kind of 23 year old... Peter Pan complex", noting his enjoyment of the structure of the song, as well as its tone.

[62] In May 2019, the band recorded a live mashup of the song with hip hop artist Lil Wayne, to promote their joint headlining tour.

[64] The track features Matt Skiba, who replaced founding guitarist Tom DeLonge in 2015, performing backing vocals and guitar.

"[65] The Fader contributor Jordan Darville noted that Wayne altered a lyric from his original verse, substituting the term "crackers" for "bitches".