Song lyrics ad infinitum

Why do we remember song lyrics even when we haven't heard them that much and even when we don't want to?  Why can't I remember Hamlet's soliloquies the way I remember the words to "Gilligan's Island" or "Mr. Ed" theme songs?

Yesterday I turned on the local pbs station and heard a raspy voice singing the words to MacArthur Park--which I remembered! (at least the chorus). 
Spring was never waiting for us, girl It ran one step ahead As we followed in the dance
Between the parted pages And were pressed in love's hot, fevered iron Like a striped pair of pants
MacArthur's Park is melting in the dark All the sweet, green icing flowing down Someone left the cake out in the rain
I don't think that I can take it 'Cause it took so long to bake it And I'll never have that recipe again, oh no
I recall the yellow cotton dress Foaming like a wave On the ground around your knees The birds like tender babies in your hands And the old men playing checkers, by the trees
MacArthur's Park is melting in the dark All the sweet, green icing flowing down Someone left the cake out in the rain
I don't think that I can take it 'Cause it took so long to bake it And I'll never have that recipe again, oh no
There will be another song for me For I will sing it There will be another dream for me Someone will bring it
I will drink the wine while it is warm And never let you catch me looking at the sun And after all the loves of my life After all the loves of my life, you'll still be the one
I will take my life into my hands and I will use it I will win the worship in their eyes and I will lose it I will have the things that I desire And my passion flow like rivers through the sky
And after all the loves of my life Oh, after all the loves of my life I'll be thinking of you and wondering why
MacArthur's Park is melting in the dark All the sweet, green icing flowing down Someone left the cake out in the rain
I don't think that I can take it 'Cause it took so long to bake it And I'll never have that recipe again Oh no, oh no, no, no, oh no

Ah, the profundity!  I read about these words on Wikipedia and found out that Dave Barry did a poll and found it the most hated song in the world. I wouldn't go that far, but I always thought it had something to do with drugs, psychodelic ones to be specific.  Not so, just a sappy "losing my love" song.

Words to most pop songs, even those from my childhood, are as immoral, hedonistic, and borderline mentally ill as one can imagine.  Billy Joel's "The Good Die Young" is blasphemy against the Catholic Church.  "If you can't be with the one you love, love the one you're with."  I could go on.  Yet there are all up there in my head, and they come to the surface very fast!