The phenomenon I am talking about here goes beyond simple memory recall. What I mean is, there are a few - very few - songs which bring back not only a memory, but bring back a whole complete set of emotions and attitudes. I not only remember the song from it's time, but I am psychologically transported to the mind-state of the point in my life the song represents. For instance, when I hear this I suddenly find I am 15 again. It's like all of the psychological changes of the past 4 decades are not only forgotten, but cease to exist entirely, like they never happened. It of course brings back vignettes - maybe screen caps is a better term - of my life at that time, but the overwhelming sensation is that of, well, being 15. With all the freedom from worry and optimism that entails.
There are two or three others, and every time I hear them it is always the same. And every time I hear them and experience the sensations I find myself wondering about it, why it works the way it does, and why just with those songs. Or why this song transports me to (in a sense remember) an age before I can even remember. I was only 5 when it was popular, but it causes that same kind of thing, only without any "screen caps" to go along with it. No memories, no real associations, just the sensation.
The old commercial tagline was "A mind is a terrible thing to waste", and it as true today as it was then. (probably needs to be said more today than then, but that is for another post!) But things like the above phenomenon reminds us that, even though we know how valuable our minds are, and thus would never want them wasted, we understand them - really understand them - very little indeed.