It’s September 2nd which means the internet has already been flooded with talk of Pumpkin Spice Lattes, back to school, and “Wake Me Up When September Ends”. But what is that Green Day song really about?

The song was actually written about Billie Joe Armstrong’s father Andrew, who passed away of cancer on September 1st, 1982 when Billie was only 10 years old. During the funeral, he started crying and ran home to lock himself in his room. Later, when his mother came back, she knocked on the door and he just replied: “Wake me up when September ends”.

In the song, the lyrics “seven years has gone so fast” are referring to Green Day’s first band called Sweet Children, which got together seven years after the tragic event. Then later in the track, the lyrics “20 years has gone so fast” refers to when the song was written, 20 years after his father’s passing.

“Wake me up when September ends” was actually supposed to be on Green Day’s 2002 album Shenanigans, but the frontman didn’t think he was in the right emotional state to record it, so they waited and used the track on American Idiot.