Paracetamol is a kind of pain reliever, so when McKenna sings about a "paracetamol smile," it refers to one that is not truly feeling the pain behind it. The song deals with sensational and depressing media coverage and how it affects young people (he was just 16 when it was released).
McKenna explained: "I just wanted to put in perspective things that people do that can be seen as kind of normal, can actually be harmful. And I tried to write from that perspective of the media, sort of written like a newspaper article, which is kind of negative and bad - I was almost poking fun at that. I just wanted to say something that talked about normal people doing something to make a change."