What if the human mind is far more similar to the modern day computer than we realise; maybe the human mind stores memories in a less organic way than originally thought? The reason why our brains are presently better than computer storage (until 2020 that is) might be the brain’s ability to evolve in memory-storage methods.
Children, with fresher minds, store memories with a relatively simple encoding, which have to be decoded using a similar method or cipher when required to be remembered or brought forth. As we age, our minds develop – being able to store greater volumes and largely more intricate memories by using evolved ciphers and encoding methods.
Maybe when we are exposed to a regressed state, such of that provided in a temporary state by certain narcotics or a more permanent state by means of tragic mental damage, our brains cannot cope with decoding the recent (or semi-recent) information stored using evolved and conditioned memory storage methods, leading to inexact or incomplete remembrance of recent events.
Conversely, in this state the mind the easily decodes memories made years earlier; and this may also lead the subject to experience 'flash backs' of very early memories. The mind may also slip into using the same touch-points of adolescent references, and will proceed to associate ideas, thoughts, objects and relationships to names and views once created and used many years before.
Maybe the dynamic encoding/decoding of memories could also play a part in old-age mind-behaviours or disease. As the brain reaches old age not only the methods of encoding memories loses it’s effectiveness but also the decoding. The inability to remember may come from the decoding ability slackening, this by incomplete decoding or the unable to regress to the previous ciphers used to encode earlier memories.
Maybe the common 'on the tip of my tongue' effect might be cause in the brain partly decoding certain information, while searching or trying out different ciphers in hope of finding the correct one to use to decode the remainder or information. This is way it often helps remembering something related to the thought or memory or one made at a close time to the creation of the memory. This will often trigger the brain to decode the memory in entirety as it has successfully used a similar cipher to decode the related thought or memory.
Although...
I'm not student of biology, or psychology; it's just a thought...