You’re living in a world you perceive accurately and react to rationally, right? Well, not exactly. Your brain reacts the way it’s been trained to react, and you’ve been training your brain without knowing it. Here are some of the ways you’ve shaped your brain, and that your brain in turn shapes your world.

Neurons that are used a lot develop a coating called “myelin.” Myelination helps you build a mental model of the world, a model that permits you to maneuver through life efficiently and safely.

Behaviors that are repeated create heavily myelinated circuits that are extremely fast, so you tend to want to keep repeating them. When you use neurons you haven’t greased, it just doesn’t feel right, so you prefer to return to familiar behaviors.

Neurons that aren’t being used wither away. This starts happening around the age of two, part of the process of having a focused worldview.

The brain builds rich interconnected networks based on what it’s exposed to. The brain seeks familiar experiences and avoids unfamiliar ones, with some neurons atrophying as a result.

Electricity does not flow easily through the brain unless pathways have already been created for it in the form of developed synapses. A synapse that hasn’t been crossed before is hard to cross, but a developed synapse makes it easy for one neuron to activate the next.

A synapse is immediately altered by an emotion, which is actually a neurochemical, though a synapse that’s activated many times through repetition also becomes an efficient transmitter of electrochemical signals.   

Synapses grow and change based on the firing patterns of neurons. The brain rewires itself based on its experiences. Our thought processes have a basis in the way are synapses are connected, but it feels to us as if we’re simply seeing the truth. 

5. Keep Smiling to Keep Smiling Happy chemicals such as dopamine or serotonin need to find receptors in order for neurons to fire and for you to know what you’re happy about. Receptors that aren’t used for a while disappear. To be happy, you have to have receptors for being happy. You can nurture dopamine and serotonin by setting goals and focusing on your wins.