Songfacts®:

• This song finds Barns Courtney singing about his life growing up in suburban Seattle in the late '90s playing video games and watching Pokémon. He told ABC Radio: "'99' has got genuine sadness, but it's got playfulness, and it references the nerdy parts of my personality where I'm in Seattle... with my friends in front of a TV screen playing Nintendo 64."
• Barns Courtney nods to a famous Prince song when he sings "We're gonna live just like it's 1999."
• The song finds Courtney lamenting the societal expectations that come with getting older. "'99' is about the needless formalization of fun as we age, and the strange ritual and transition from childhood into adulthood," he explained to Radio.com. "I think society is sick with this strange and horrendous bug called adulthood."
• The song sat around for three years as Courtney couldn't come up with a satisfactory chorus. Eventually, he and his English songwriting partner Sam Bartle came up with a hook after pounding away for a week in Bartle's childhood bedroom. He told HMV: "We drove ourselves crazy doing that one."
  
  Bartle's childhood home is in the Cambridgeshire village of Yaxley in England. Courtney recalled to EV that they completed the song "in the middle of nowhere, January, dark, raining sideways, in this place that I hadn't written in since I was a teenager when we first started working together."