Fade

People used to say that memories fade over time. But the science says that it's not so much a loss of clarity as it is a loss of access. Neural pathways to the memory pruned away until only one or two are able to trigger recall. Or overwritten so many times that the memory has not only become more vivid, but even altered with added or edited details.
But what happens to memories that are not stored in a living mind? Perhaps the quantum abnormalities generally classified as ghosts, or haunts, are actually memories that have imprinted on a place or thing.
Like photographs, they slowly lose the original colors. Crisp black and white mellows into sepia tones. Details and colors dissappear behind a veil of purple haze as the tints degrade.