Forgetting or disremembering is the apparent loss or modification of information already encoded and stored in an individual's short or long-term memory.

Problems with remembering, learning and retaining new information are a few of the most common complaints of older adults.

[2] Forgetting curves (amount remembered as a function of time since an event was first experienced) have been extensively analyzed.

A healthy diet can also contribute to a healthier brain and aging process which in turn results in less frequent forgetting.

Using himself as the sole subject in his experiment, he memorized lists of three letter nonsense syllable words—two consonants and one vowel in the middle.

[7] Around the same time Ebbinghaus developed the forgetting curve, psychologist Sigmund Freud theorized that people intentionally forgot things in order to push bad thoughts and feelings deep into their unconscious, a process he called "repression".

[5] Concerning unwanted memories, modern terminology divides motivated forgetting into unconscious repression (which is disputed) and conscious thought suppression.

[12] This method measures forgetting by the amount of training required to reach the previous level of performance.

This theory states that a memory is sometimes temporarily forgotten purely because it cannot be retrieved, but the proper cue can bring it to mind.

A good metaphor for this is searching for a book in a library without the reference number, title, author or even subject.

[15] These specific studies have shown that episodic memory performance does in fact decline with age and have made known that older adults produce vivid rates of forgetting when two items are combined and not encoded.

Examples include Alzheimer's, amnesia, dementia, consolidation theory and the gradual slowing down of the central nervous system due to aging.

Interference theory refers to the idea that when the learning of something new causes forgetting of older material on the basis of competition between the two.

[18] This theory shows a contradiction: an extremely intelligent individual is expected to forget more hastily than one who has a slow mentality.

For this reason, an intelligent individual has stored up more memory in his mind which will cause interferences and impair their ability to recall specific information.

[19] Based on current research, testing interference has only been carried out by recalling from a list of words rather than using situation from daily lives, thus it is hard to generalize the findings for this theory.

[20] Peripheral processes such as encoding time, recognition memory and motor execution decline with age.

Suggesting contrary to earlier reports that the inhibitory processes observed with this paradigm remain intact in older adults.

Decay theory states the reason we eventually forget something or an event is because the memory of it fades with time.

[16] According to this theory, short-term memory (STM) can only retain information for a limited amount of time, around 15 to 30 seconds unless it is rehearsed.

One major problem about this theory is that in real-life situation, the time between encoding a piece of information and recalling it, is going to be filled with all different kinds of events that might happen to the individual.

[citation needed] Sleep is believed to play a key role in halting trace decay, although the exact mechanism of this is unknown.

This theory can be criticized for not sharing ideas on how some memories can stay and others can fade, though there was a long time between the formation and recall.

An inability to forget can cause distress, as with post-traumatic stress disorder and hyperthymesia (in which people have an extremely detailed autobiographical memory).

"Social amnesia" was first discussed by Russell Jacoby, yet his use of the term was restricted to a narrow approach, which was limited to what he perceived to be a relative neglect of psychoanalytical theory in psychology.

[25] In an in-depth historical study spanning two centuries, Guy Beiner proposed the term "social forgetting", which he distinguished from crude notions of "collective amnesia" and "total oblivion", arguing that "social forgetting is to be found in the interface of public silence and more private remembrance".

[26] The philosopher Walter Benjamin sees social forgetting closely linked to the question of present-day interests, arguing that "every image of the past that is not recognized by the present as one of its own concerns threatens to disappear irretrievably".