Arthur C. Clarke said this quote

“ What is human memory? Manning asked. He gazed at the air as he spoke, as if lecturing an invisible audience - as perhaps he was. It certainly is not a passive recording mechanism, like a digital disc or a tape. It is more like a story-telling machine. Sensory information is broken down into shards of perception, which are broken down again to be stored as memory fragments. And at night, as the body rests, these fragments are brought out from storage, reassembled and replayed. Each run-through etches them deeper into the brain's neural structure. And each time a memory is rehearsed or recalled it is elaborated. We may add a little, lose a little, tinker with the logic, fill in sections that have faded, perhaps even conflate disparate events. In extreme cases, we refer to this as confabulation. The brain creates and recreates the past, producing, in the end, a version of events that may bear little resemblance to what actually occurred. To first order, I believe it's true to say that everything I remember is false. ”