Run DMC???

So, all day I have had the song "Mary, Mary, Why You Buggin'?" in my head. Now, my musical tastes are more Joe Strummer than Joe Simmons, but I'm not complaining.

Usually when I get a song stuck in my head it's something by Hall and Oates. Or that Bonnie Tyler song, "Total Eclipse of the Heart." Hell's not other people; hell is the Bonnie Tyler song being reproduced by your very own treasonous brain. Over and over and...

So I am TOTALLY fine with Run DMC.

But how the hell did it get in my head? I must have heard it recently, but I can't figure out where. How else would a song I haven't heard in 15 years get stuck in my head?

So here's the philosophical question: If I have a song stuck in my head, where does it come from? If, say, I have been plagued by “Copacabana” replaying in my head for several hours, does the 50th iteration have the same source as the first? Barry Manilow is presumably the source of the first time--when I *heard* the song. But the second time it plays in my head, is Barry Manilow still the origin, or is the first iteration the origin? And why was I listening to Barry Manilow?

If a tree fell in the forest, would the sound drown out the Bonnie Tyler song?

Please?

P.S.
I have been trying out variations, trying to get the song in my head to change a little. Part of the problem is that I really only know the refrain of the song, so it's just this brief bit that keeps getting recycled. So I'm trying to work it out a little.

My Post-Steroid Pep Talk to Bonds:

Barry, Barry, Keep on Sluggin'

My Tribute to Seinfeld:

Jerry, Jerry, Why You Shruggin'?

My Farewell Ode to the President of Harvard:

Larry, Larry, What a Hole You're Dug In!

A Cautionary Tale About Joseph Hazelwood:

Ferry, Ferry, That's Oil You're Gluggin'

ok--now I've got "Ferry 'Cross the Mersey" stuck in my head.

It's different, anyway.