Remembering problem...why is that? ?

Why is it that people can remember the song lyrics to every song on their Ipod but they can't remember important things like their homework ignments or where they took their shoes off? Me and my friend suffer from the same problem. I can remember the most random facts ever and quote tons of movies and songs but I can't remember what I had for dinner last night. She can remember every song there is to remember but can't remember where she put her phone. Is it that we don't want to remember that kinda stuff? Or is it we are just forgetful?