Neurons never work alone. And they aren’t just connected to one other neuron in a chain. Instead each neuron is one unit in a complex network of connections. Scientists estimate a single neuron can make up to 8,000 connections with other neurons. And the activity of one neuron influences many others. The adult brain contains about 86 billion neurons. If each of those 86 billion neurons makes 8,000 connections, the complexity of the system quickly becomes hard to grasp. The neurons in the brain form the most complex network in the known universe.

And we each have one! These trillions of connections in our brains are what allow us to learn and adapt throughout our lives.