You leave the school, walking home alone in hopes of clearing your head a little. As you walk you whistle a sad little tune. The tune drifts over the air and through the streets of your town. A barber picks it up as he sweeps his shop. The meter maid whistles it as she writes tickets. Soon there's a whole chorus of meloncholy whistlers for no better reason than the genre being a musical.
By the time the whistling stops, you're completely lost and have forgotten what you were doing, if anything. You seem to have been whistling up the railroad tracks, but you're not sure where any tracks would be.