the problem with blueberries

funny thing, blueberries. you could be eating a bowlfull of them, just-bought and just-washed, munching away without paying attention to which exact berry you are eating, content with the uninterrupted stream of sweetness into your mouth, and there it is: the sour one. you feel confused. you know every blueberry you saw when washing was lovely and round and sweet. you feel betrayed. you can't enjoy eating your blueberries any longer as you are suspicious of each one. you do though (why waste blueberries?), but the experience is certainly not the same as it was.

i think this must be a metaphor for something. for what i don't know.