Flashback Friday Song of the Day - Who Knew - P!nk

I remember watching P!nk on VH1 Storytellers talking about the meaning of this song.  Before that I had always thought that it was about a lost love, which is what is may seem from the lyrics, but that wasn't it at all.  She said she'd written it for a friend she had in high school, one of the school jocks, who'd accidentally died from an overdose.  She continued to say that over the years, whenever she performed the song, the person she thought about and for whom it became would change as various people in her life passed away, her grandmother, her friend, even her dog.  Well, today I'm borrowing that song for my sister as we say goodbye to her for the final time.  It's going to be a difficult day.  Sigh!