“18” is the fifth track on 5 Seconds Of Summer’s self-titled debut. It’s a bouncy track about the troubles of age and dating someone who’s older. It was also the first track on their live album LIVESOS.

Billboard thought positively of it, with editor Jason Lipshutz saying:

The entire appeal of 5 Seconds of Summer’s style is on display on “18,” a legitimately funny, insanely catchy ode to the frustration of waiting for adulthood when you’re still a punk kid. The guys effortlessly sell lines like “She’s got a naughty tattoo/In a place that I want to get to/But my mom still drives me to school,” bouncing along with the Ashton Irwin’s snappy percussion and sounding like they’re having a blast with the concept.