A mental block is an uncontrollable suppression or repression of painful or unwanted thoughts/memories. It can also be an inability to continue or complete a train of thought, as in the case of writer's block. In the case of writer's block, many find it helpful to take a break and revisit their topic. Another tactic that is used when people with mental blocks are learning new information is repetition. A similar phenomenon occurs when one cannot solve a problem in mathematics which one would normally consider as simple. Mental blocks can be caused by physical disabilities or simply a lack of focus. Mental blocks are also often used to describe a temporary inability to recall a name or other information. A sudden cessation of speech or a thought process without an immediate observable cause sometimes can be considered a consequence of repression.^{[unreliable medical source?]}

Forgetting curves could be associated with mental blocking. The forgetting curve was first described by Ebbinghaus as the natural loss of memory retention over time. Memories can also simply disappear over time from Trace decay which is the weakening of memories over time. This kind of decay stems from both the visual and verbal working memory. Although this triggers decay, some of the information remains stored. Interference is the phenomenon that a memory can be distorted due to the existence of related memories when it comes to retrieval.

Although incidental forgetting is unintentional, it is an important process. A person's brain can become overwhelmed with information, so it is beneficial when unneeded stored information is forgotten. Two interferences are associated with incidental forgetting, proactive and retroactive. Proactive interference is the effect on a person's ability to recall information on a learned subject. An example of this would be a person having trouble remembering a friend's new address when they had the old addresses memorized. Retroactive interference is when new learning affects one's memory on a previously learned task. An example would be an actor learning new lines for an upcoming episode they are filming. When they are learning the new script, this could affect their ability to remember the script that went along with the previous episode. Another interference that some scientists believe is the main culprit of incidental forgetting is one's ability to pay attention which therefore hinders one's brain's ability to properly encode the learned information.

A noteworthy cognitive research study showed study participants a 9-minute video about recognition-induced forgetting. This followed a series of tests that evaluated the participant's comprehension after watching the video. Because the participants watched this video, they were aware of unintentional forgetting and how it occurs. Still, participants fell victim to incidental forgetting when being tested on what they were supposed to remember from the video shown. This led researchers to believe that even when people are aware of the phenomenon of incidental forgetting and challenged not to forget, they still have trouble remembering.

Incidental forgetting differs from incidental forgetting at a rapid pace. Losing memories at a rapid pace is an indicator of amnesia, dementia, mild cognitive impairment, and other conditions that can be caused by age or a traumatic injury.

Associative blocking is explained as the effects of an interference during retrieval. Associative blocking can be caused by the failure of a cue to reach a specific target because the cue is being replaced by a new cue that grows stronger. This causes the initial cue to deteriorate because each separated memory is competing for first access to the conscious when the shared cue is presented. When interference occurs, two memories that are similar to each other are competing to be remembered. Therefore, the recall of one of those two memories will be more difficult to decipher. To avoid the interference theory from affecting one's recall between multiple memories, researchers say to make it memorable.

Unlearning is associated with two separate stimuli that are attached to a memory trace; the trace is then weakened because it isn't accessed often enough. When one attempted to recover said memory an error happens when a different cue is presented. The studies regarding unlearning are now being associated with interference theory. Interference theory can be defined as the how and the why of long-term memory loss. This theory also suggests that the more information someone learns at one given time, the more quickly they will forget.

The process of unlearning does have positive qualities. Unlearning can be helpful if the information being stored was false or untrue. However, confirmation bias can make it more difficult to unlearn. This is due to the information supporting one's beliefs or views. Decay theory is believed to play a role in the unlearning process as well.