Although there is a preconceived notion that forgetfulness is thought of as a negative consequence of the brain, it actually happens to be a necessary and arguably beneficial function.

The brain is the control centre of the body and mind, comprising billions of neurons that allow us to function and thrive the way that we do. The stronger the memory recall, the stronger the neural connection, and vice versa.

So, why do we forget?

Earlier research suggested a passive process involving the cleansing of old memories that were unused for a period of time. This passive process was known as decay. However, in recent years, a greater understanding of the brain has been achieved.

The discovery? The brain happens to be coded to forget, intentionally and purposefully. This active process is what comprises the latest body of evidence regarding the brain, its memory, and its forgetfulness.

Why Does the Brain Forget?

In short, research suggests that actively forgetting memories is what allows us to retain and remember new ones. In fact, the more we understand the true functionality of the brain, the more we understand that forgetfulness is, though contradicting, what allows our memory to function properly.

In other words, without the ability to forget, our brain would have no memory at all.

The fact of the matter is that while the brain and its billions of neurons have grand capacities, its ability to remember and recall is limited. This is, in part, due to several factors.

Below is a summary of why the brain forgets and what’s to blame for this lapse in functionality:

Decay

The Decay Theory suggests that if a particular memory is not regularly recalled and rehearsed, it decays and disappears from our memory over time.

Interference

Obviously named, this phenomenon suggests that when two memories are similar in nature, they tend to interfere with one another. This ultimately results in a confusion of memory and an inability to remember an old or new memory.

Lack of Storage

The failure to store a memory in long-term care. If a memory lacks specificity, it likely fails to get stored for long-term recall.

Intentional Forgetfulness

Sometimes we as humans are simply motivated to forget. This may be due to a negative experience, traumatic event, or unpleasant memory of sorts. As such, suppression of memories occurs, ultimately resulting in forgetting it over time.

Lifestyle Factors (i.e. substance consumption, mental illness, stress, poor sleep, etc.)

Several lifestyle factors are associated with forgetfulness as well. While the majority of them are controllable, if not controlled, a lapse in memory will be the result.

How Does the Brain Forget?

So, what’s to blame for how and why we forget? In short, the hippocampus…

The hippocampus relies on several storage mechanisms when it comes to memories and recall. Depending on how a particular memory is stored and categorized will largely determine whether or not the brain forgets it in time.

Another reason for memory loss and forgetfulness is a neurological condition known as neurogenesis. While neurogenesis is largely a positive outcome for the brain, it’s been shown in research to lack old memory recall.

In other words, while the birth of new neurons allows the brain to store new memories, among other functions, it seems to eliminate the ability to continue to retain and recall old memories.

Although it’s still unsure why this occurs, it’s likely related to the decay and interference mechanisms of memory storage.

No matter the cause of memory or lack thereof, forgetfulness is caused by the degeneration and regeneration of neural cells, the remodelling of neural pathways and thought patterns, and a shift in the hippocampus circuitry.

Final Thoughts

While the brain’s ability to forget has previously been thought of as a negative consequence of several factors, new research is suggesting the contrary, proving its purpose is good.

Forgetting is a function of how memories are stored. In other words, memories that we regularly recall are likely to stick around, while memories that we ignore are likely to decay over time.

There is a lot we still don’t understand when it comes to the brain and its functionality, memory and forgetfulness included. While more research certainly needs to be done, there’s no doubt that modern science has shown, at the very least, the value of forgetting when it comes to the function of memory at large.