I just can’t get it out of my head.

You’re driving along, minding your own business when a truly great song from your teen years comes on.  You loved that song.  Six hours later, you can’t get rid of it.  You’re losing your mind.  That song is likely to have a greater “stick factor” because it’s upbeat, has a fast tempo and a generic and easy to remember melody.  It’s a unique song.  Most of us, 90%, get an “earworm” like your song, stuck in our heads at least once a week.  It happens when our brains aren’t doing much such as taking a shower or a walk or doing mindless chores.  The brain is always searching for something novel to focus on and a song is a great target.  What do you do to keep your sanity?  Embrace the song.  Listen to a lot of songs.  Don’t work hard to avoid it.  That’s not the way the brain works.  The more you try not to think about it, the more you’ll hear it.  It will fade on its own.