Pulled some stuff form our lesser regarede source, Wiki.

Disorders

"Much of the current knowledge of memory has come from studying memory disorders. Loss of memory is known as amnesia. There are many sorts of amnesia, and by studying their different forms, it has become possible to observe apparent defects in individual sub-systems of the brain's memory systems, and thus hypothesize their function in the normally working brain. Other neurological disorders such as Alzheimer's disease can also affect memory and cognition. Hyperthymesia, or hyperthymesic syndrome, is a disorder which affects an individual's autobiographical memory, essentially meaning that they cannot forget small details that otherwise would not be stored.^[10] Korsakoff's syndrome, also known as Korsakoff's psychosis, amnesic-confabulatory syndrome, is an organic brain disease that adversely affects memory.

While not a disorder, a common temporary failure of word retrieval from memory is the tip-of-the-tongue phenomenon. Sufferers of Nominal Aphasia (also called Anomia), however, do experience the tip-of-the-tongue phenomenon on an ongoing basis due to damage to the frontal and parietal lobes of the brain.."

Ripped from a Wiki post about Memory.

I found this VERY interesting as my dad’s side of the family has Alzheimer's in its history, and reading this reminded me of a previous memory, perhaps one of the negative sides of memory loss is its ability to also allow you to re-remember and endure again, previous nightmares.
A few years back, as of when I'm unsure, I remember awaking in tears after having a dream this I was locked away in a mental hospital, Hellsdon to be exact, and this is a common thing about dreams and nightmares, they have to spawn from some sort of fictional sense, because you brain has to replicate these dreams from events that your body has itself had to deal with.
That’s why you never die in dreams, because your brain has not, obviously, died or experienced death.

In this dream I was a normal man, but because of my desperation to not go to this hospital, I acted somewhat irrationally and thus looked even more mentally unstable. So it would seem that I'm very afraid about being misjudged, that’s my analysis of that dream, no idea as to its exact date, it just came back to me when reading that text about disorders, and I felt it relevant to add here since this is all about memory.