Songfacts®:

• All Time Low close their fifth studio album, Don't Panic, with this sarcastically-titled track, which frontman Alex Gaskarth told Billboard magazine, "is obviously a send-off and a farewell and a big 'f--k you' to some of the people from our past that tried to steer us in the wrong direction."
• The song's title comes from a line from Douglas Adams' series of comic sci-fi books and comedy TV series, The Hitchhikers Guide to the Galaxy - "So Long, and thanks for all the fish."
  
  The album title also comes from the The Hitchhikers Guide to the Galaxy. It references a phrase written on the cover of the titular electronic travel guide, which is featured throughout the series.
• Gaskarth told Billboard magazine that much of the writing for the album was done on the road. "I would say the first half of the record was written while we were on tour over the fall of 2011," he said. "We wrote the second half of the album in the studio in the beginning of 2012."
• Here are a couple more songs that reference The Hitchhikers Guide to the Galaxy:
  
  1. "42" by Coldplay.
  
  2. "Paranoid Android" by Radiohead.
  
  Also, the English jazz-funk band Level 42 took their name from an explanation in the book that the Answer to The Ultimate Question of Life, the Universe, and Everything, is "42."