You ever have deja vu? The brain associates many things together, and can often give you the visceral feeling that you've been there before. For several years I have had a very specific deja vu that I have finally tracked down. I found for some reason that when I watched the movie Unbreakable (great movie!) that later in the day I would recall a video game in my distant past called the Legend of Zelda, that I played on our Nintendo game machine. This happened a couple of times, so I felt there was some association that I couldn't quite pick up.
Then I noticed that each time, I was humming the theme song to Zelda during the day, and I finally figured out the association: the musical transitions in the themes are close enough that hearing one, I would continue with the other. The clips are below. If you listen to about 30 seconds of the Unbreakable music, you'll get the theme, and then go back to the Zelda clip. How random! But now I have the satisfaction of a puzzle solved!