Songfacts®:

• BTS' fifth Korean-language studio album, BE, was created in response to the 2020 coronavirus pandemic. During this electro-pop inspired track, the boy band sing of being separated from their fans (ARMY) as they are not seeing them anymore during live performances. They feel all their memories of their fans are just a dream.
• At a press conference, BTS' Jungkook explained the song serves as an encouragement to ARMY. Though there is a geographical distance between band and fan, they remain with them. "We are far apart physically but we always stay together," he said. "That's the message we wanted to put into this song."
• The BTS members who performed on "Stay" - Jungkook, Jin and RM - wrote the lyrics between them. The song was originally intended to be the last track on Jung Kook's mixtape with entirely English words. When they recorded it instead for Be, they partially changed it to Korean but kept the original title.
• Jungkook and Jin sing the opening lines.
  
  Was it a dream?
  I think I saw you
  When I open my eyes again
  The room's empty
  
  Jin came up with the song's theme. He explained to Weverse magazine: "We used to see our fans and it was great, but now that's something we can't do anymore. I thought it all felt like a dream. I wanted to say, 'We used to be so happy together, but now I feel like your very existence was a dream.' I came up with the intro and then talked about it with RM. He really helped me a lot."
• Belarusian EDM producer Arston supplied the instrumentation. He explained to Bandwagon: "We all now live in a world of isolation, we don't go to concerts, clubs or festivals. Therefore, I wanted to create a track that is both energetic and danceable, but at the same time with a chill, cozy home party atmosphere. And I'm very glad that this mood suited well for the great song that the guys wrote."