In a creative writing class I took in college, the professor represented stories and poems that "ring true" as plucking a string running through your soul (essence, being, whatever). Over time I've subclassed this notion to be multiple strings, each attached to a strong feeling or experience.
The worst of these is sorrow attached to a death, and when something jumps up out of nowhere and plucks that string I feel powerless, like a walking bundle of emotions where seconds earlier I was "in control" and "myself". What a fragile creature. (In this case, the plucker was that Aimee Mann "Wise Up" sequence during Magnolia while flipping around at 3 am due to insomnia.)
(Originally posted elsewhere)