Hayley Williams has described this song as one whereas she is addressing a “younger, weaker version” of herself. But this isn’t one of those general-advisory kind of scenarios. Rather she is harping on a particular event, i.e....
It is very much likely that Hayley Williams is speaking to a romantic interest on “Why We Ever”. However, it can also be interpreted as another type of really-close friend. And the titular question is based...