The human brain consists of about one billion neurons.
Each neuron forms about 1,000 connections to other neurons, amounting to more than a trillion connections.
Neurons combine so that each one helps with many memories at a time, exponentially increasing the brain’s memory storage capacity to something close to around 2.5 petabytes (or a million gigabytes).
For comparison, if your brain worked like a digital video recorder in a television, 2.5 petabytes would be enough to hold three million hours of TV shows.