"What's My Age Again?" is a song by American rock band Blink-182. It was released in April 1999 as the lead single from the group's third studio album, Enema of the State (1999), released through MCA Records. "What's My Age Again?" shares writing credits between the band's guitarist Tom DeLonge and bassist Mark Hoppus, but Hoppus was the primary composer of the song. It was the band's first single to feature drummer Travis Barker. A mid-tempo pop-punk song, "What's My Age Again?" is memorable for its distinctive, arpeggiated guitar intro.