"What's My Age Again?" has endured as among the band's most popular songs, and has widely been considered a watershed moment for pop punk as a genre. 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.
Rolling Stone 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?" and "All the Small Things" was hugely influential." Twenty years after the song's release, Hoppus noted that fans often decorate
birthday cakes on their 23rd birthday with the lyric "Nobody likes you when you're 23", which he felt was an honor. The band later paid homage to the song's infamous video in the music video for their 2016 single "
She's Out of Her Mind". The clip sees modern-day
social media personalities running in the nude in Los Angeles. Lindemulder's place in the video was taken by actor and comedian
Adam DeVine.
The Hollywood Reporter Mischa Pearlman, in a review a 2013 concert by the group, wrote that the song "visibly infects every member of the audience. Because it's a song that recalls the reckless abandon of youth, and the carelessness of growing up." Although the magazine gave the song a scathing review upon its initial release,
NME placed it at number 117 on its list "150 Best Tracks of the Past 15 Years" nearly thirteen years later, writing, "Few songs capture the urge of wanting to act stupid and be immature as well as this 2000 single does. [...] This is everything pop punk does well. Its guitar riffs seem to have been soaked in Relentless and its chorus makes you want to jump around the room. It's been imitated thousands of times since, but nothing's come close to this..." 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?", described as a night celebrating "pop-punk, youthful abandon and teenage riot". British radio station
BBC Radio 1 have a section on one of their shows named after the single and using it as the theme song.
Greg James originated the game on his drivetime show, and has moved it to
The BBC Radio 1 Breakfast Show. The game sees Greg pitted against an opponent, typically a fellow Radio 1 DJ/presenter or celebrity guest. In the game, three listeners phone in and talk to the competitors, who take it in turns to ask questions, then try to guess the listeners' age. On March 26, 2019, the song was lauded by
Princeton professor of music
Steven Mackey during an interview between Hoppus and Mackey given at Princeton University. 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. Mackey stated, "after the second chorus there's this instrumental break. And there's a lot of instrumental breaks in Blink, which I really like. This one in particular, it goes to a
minor key. All of a sudden, it's kind of melancholy. And when they come out of that instrumental break, and I hear the rest of the words, it's sort of like... I feel like, wow, was that a moment of reflection? And then it's like, 'Ah, fuck it. Whatever.' It has that feeling. It sort of deepens it for me." In 2023, the song was used in the trailer for the reboot of
Clone High. In 2024, the song was later included in
Fortnite in
Fortnite Festival as a jam track. ==Mashup==