Songfacts®:

• In the period between 2017's Gossip and 2019's How It Feels To Be Lost, Sleeping With Sirens' vocalist Kellin Quinn found life to be a real struggle. Wracked by depression and anxiety in the midst of the band's hectic touring schedule, the singer struggled to hold it together. During this song, Kellin recalls the darkness that enveloped him during that period.
  
  Would you be so surprised if I gave up tonight?
  I'm barely breathing, I wanna kill the pain I feel inside
  But I won't quit for the people I love
  
  Kellin recalled to Kerrang: "The message of the song is very poignant. We all struggle with thoughts in our mind sometimes, asking questions like, 'What is my purpose?' and 'What is the point of everything?' When life gets hard, these thoughts can run around your head, so I wanted to play with the idea of that and push these feelings to the edge. Leave It All Behind talks about weighing up your life and deciding whether it's worth sticking around or giving up. It's a very dark mindset, but it's honest, and I think we have to be honest with ourselves when it comes to subjects like depression and anxiety."
  
  Kellin added that he is not alone in struggling with life as so many young people today are struggling to find their purpose; however, this is a song of hope.
  
  If you feel like you are nothing
  If you feel like letting go
  I'll be your hope if you are hopeless
  We are not alone
  
  Kellin told Kerrang: "That's an important message to portray, because those dark thoughts can make you feel like you're by yourself, but they're feelings that many people experience. I've been in that place over the past couple of years, and I wanted to let people know that they're not alone."
• Sleeping With Sirens debuted "Leave It All Behind" during their performance at London's All Points East Festival on May 21, 2019.
• Kellin wrote the treatment for the song's music video on a flight to LA while the band were finalizing what the singles for How It Feels To Be Lost would be. He said:
  
  "I've always been interested in special effects, and you see loads of music videos which are just your standard 'band in a room' thing. It's a concept that's been done to death, so I wanted to focus on a real character, and use that to analyze how I see myself and my struggles. The video covers my recent experience with depression and anxiety and coming to the end of that period. There are a lot of interesting elements to the video, not least me falling out of a window! I think it's awesome."