My wife, my son and his piano teacher all have perfect pitch. Me and my daughter don't have it. Watching my kid figure out pitch is interesting because sometimes he will know, and other times he'll use a reference note, like middle C and then get the notes from there. When we listen to a song, I will ask him what scale the song is in, and he'll dissect it to figure out. It's all fascinating to someone like me who has no concept of perfect pitch.