Songfacts®:

• This nostalgic pop-punk tune finds Mark Hoppus recalling his youth when he longed for a better reality.
  
  I wanna feel happy days, happy days.
  Happy days, happy days
  All of this frustration inside of my brain
  And I don't know if I'm ready to change
  
  Hoppus explained to Zane Lowe on Beats 1: "It's about coming from a place of frustration and angry and saying, 'I want to go to better times, I want to go to a better place and I'm gonna leave all this nonsense behind and just find my zone.'"
• The song was released on July 1, 2019 - the 182nd day of the year. The band said they dropped it on that date to celebrate blink-182 day.
• This was the first track released by blink-182 since Tom DeLonge's departure from the band that features vocals solely from Hoppus and is longer than 30 seconds.
• Blink-182 wrote the song with producer Tim Pagnotta and lyricist Sam Hollander. The band also worked with the pair on "Blame It On My Youth."
• Blink-182 were wrapping up the recording of Nine and thought they'd go into the studio one more time to see if anything happens. Hoppus recalled to Genius:
  
  "We got in the studio, we started talking. We were talking about negative thoughts, the thoughts that creep into your head when you're awake late at night and that sometimes you have to push through that and make yourself get to a better place. And that's what this song is about."
• Mark Hoppus told Kerrang: "'Happy Days' is me talking to myself about trying to pull myself out of the depression and self-doubt I fall into far too often, even now."
• Released in April 2020 amid the coronavirus pandemic, the video was compiled from footage sent by fans showing how they're spending their time while quarantined at home, mixed with clips of the three Blink-182 band members performing the song from the comfort of their own houses.
  
  Andrew Sandler helmed the visual. The director previously worked with the band in their "Darkside" video.