The trouble with memory is that often it plays us false. We may not remember an event exactly as it happened. Another witness may remember it differently. Here is Dr Johnson’s view of the matter, written well before we had such conveniences as camera phones to help – a little.
There is yet another cause of errour not always easily surmounted, though more dangerous to the veracity of itinerary narratives, than imperfect mensuration.
An observer deeply impressed by any remarkable spectacle, does not suppose, that the traces will soon vanish from his mind, and having commonly no great convenience for writing, defers the description to a time of more leisure, and better accommodation. He who has not made the experiment, or who is not accustomed to require rigorous accuracy from himself, will scarcely believe how much a few hours take from certainty of knowledge, and distinctness of imagery; how the succession of objects will be broken, how separate parts will be confused, and how many particular features and discriminations will be compressed and conglobated into one gross and general idea.
To this dilatory notation must be imputed the false relations of travellers, where there is no imaginable motive to deceive. They trusted to memory, what cannot be trusted safely but to the eye, and told by guess what a few hours before they had known with certainty. Thus it was that Wheeler and Spon described with irreconcilable contrariety things which they surveyed together, and which both undoubtedly designed to show as they saw them.
from “Journey to the Western Islands of Scotland” by Samuel Johnson.
George Wheeler and Jacques Spon rediscovered the site of ancient Delphi, using an old description from Pausanias, and published their findings in 1682. I wonder, what will be the effect of all those video recordings of himself that my 20 month-old grandson likes to watch?