“Why do I hear boss music?” is a well-known reaction meme that questions boss music that the user is hearing, but for no reason at all. This line originated from a video game called Terraria, which was released in May of 2011.
The character is sitting in a UFO mount asking the user “Why do I hear boss music?”
This meme started to gain attention during the beginning of 2019 and was from there transformed into many variations. In April of the same year, Twitch user BeastrollMC unintentionally brought up this meme when he started to hear the random Pantera boss them faintly in the background.