Why We Remember Important Things And Forget Trivia: Neuron's Synapses Remodel Themselves:

Where would we be without our ability to remember important information or, for that matter, to forget irrelevant details? Thanks to the flexibility of the nerve cell's communication units, called synapses, we are good at both. Up to now, only the receiving side of a synapse was believed to play an active role in this reorganization of the brain, which is thought to underlie our ability to learn but also to forget. An incorrect assumption, as scientists can now show.[1]