“A memory that costs you something," he said aloud, almost to himself. "One that hurts to remember. That makes you regret what you did or didn't do. Or makes you remember how happy you used to be when they were here. Something that makes you really feel your grief." Those were the memories that summoned the ghosts: the ones that came at a price, that took a little something from the person remembering. These were emotions complex as flavors, sweet articulated by bitter, acid cutting through umami, fat neutralizing heat.”
Book:Aftertaste