Your Brain "Cleans Out" Useless, Left Over, Unnecessary Information

Your Brain "Cleans Out" Useless, Left Over, Unnecessary Information
Valeria Sabater

Written and verified by the psychologist Valeria Sabater.

Last update: 15 November, 2021

Unlearning in order to learn. Clearing out unnecessary information to make room for the useful and the meaningful. Our brain, strange as it may seem, also carries out the delicate task of recycling while we sleep or meditate. Purifying itself. Pulling up the “weeds” so it can create stronger connections, new thoughts, and much more useful, valuable lessons.

Sir Arthur Conan Doyle, in “Study in Scarlet,” wrote about how surprised John Watson was when he discovered yet another talent of his extraordinary roommate. Sherlock Holmes did not know that the Earth revolved around the Sun. But the famous detective had an excellent reason why he chose to forget that fact and other facts.

“I remember even what I do not want to. I cannot forget what I want.”


The human brain — explained Holmes — is like a little empty palace where you can put whatever furniture you like. Foolish people pile up pretty, shiny objects they find here and there. They don’t sort out which ones are really necessary.

Little by little, we have no room left for useful knowledge. However, a skillful craftsman is very careful with what he puts in the palace of the brain. He only allows in the tools he needs to do his work.

Almost without knowing it, Conan Doyle taught us a basic principle about the economy of internal “gardening.” It’s where the brain decides which synaptic connections to feed and which ones to destroy. And it does so based on our lifestyle, interests, experiences, and learning.

Neurologists often say that we have a metaphorical “delete button” for things we don’t need, saving us space, getting rid of unnecessary information. Then we can build new, stronger connections we can use to consolidate more meaningful knowledge. It’s a process that we can actually control. Let’s look at how.

Internal gardening: removing unnecessary information

In the brain, learning also involves “destroying”

Many of us still hold onto the classic idea that the more synaptic connections our brains have, the better. We think that’s how we learn new things and acquire new abilities, skills, knowledge. However, Sherlock Holmes’s theory actually has some scientific basis. The brain is not a palace for unconnected things we accumulate randomly and obsessively.

The brain is a sophisticated organ that likes to economize and specialize depending on its owner. Let’s look at an example. You’ve decided to learn to play the piano You’re very excited and go to class for one hour a week. In this case, the impact on your brain will be minimal. However, if you get serious and practice daily, amazing things will happen.

One of them is so-called “synaptic pruning”, in other words, in order to create new synapses and new circuits with that musical learning, the brain will first eliminate old neuronal connections that are not useful to it. Unnecessary information. It needs space and it needs to build new routes, new bridges, and untangle cables for something new to flow.

To understand this concept, imagine that your brain is a garden. Instead of flowers, synaptic connections grow there. They create routes between neurons through which neurotransmitters like dopamine and serotonin travel.

Now, for these new structures to flourish, we must first pull up the weeds. We have to rake and clear out the old leaves to make room. The “microglial cells” carry out this task, magical entities we owe our ability to learn new things to. It’s pretty amazing!

Synaptic connections.

Sleep and meditation, two strategies your brain uses to get rid of unnecessary information

We already know that our capacity to learn transcends, in many cases, our own biology. Well, in order for new knowledge to be integrated into our memory, we need to sleep. Neurologists often say that a brain deprived of sleep is like a wild forest so dense you can’t move. It’s somewhat chaotic, dark, suffocating, and overgrown with vegetation.

He who asks to forget, cannot forget when he remembers that he has asked to forget.”

-Calderon de la Barca-

To clear roads and free up space, we need deep, restful sleep. It is then when the glymphatic system springs into action. This system has the job of eliminating waste substances and all the dead cells generated by synaptic pruning.

We’re talking about sleep, but we should note that a short 15-minute nap in the middle of the day or even 20 minutes of deep mediation is also useful when it comes to making room for new neuronal connections.

A little girl sleeping with her teddy bear.

Another important thing that happens, as neuropsychologists tell us, is that sometimes just no longer focusing on anything allows us to “deactivate” that synapse and detract from it. It’s like pressing the delete button.

It’s a fascinating phenomenon worth more research…

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.