Early onset dementia?

Most mornings I wake up with a song playing in my head. Today it was Sgt. Pepper's Lonely Hearts Club Band, not my favourite tune from yesterday's Live 8 concert. If given a choice I would have picked Dido and Youssou N'Dour's Seven Seconds. That's the trouble, you see: I can't pick and choose the number. Often it's the theme song of a kid's television show, an old tune from my formative years (and the tape long since relegated to the dustbin), or a song I half-heard the day before. It's come to the point where I have to beg Kassie for a new tune before she goes off to school.