"When your ears hear a sound, they transmit it to the brain where echoic memory stores it for about 4 minutes. In that short time, the mind makes and stores a record of that sound so that you can recall it after the actual sound has stopped. This process is ongoing, whether you are aware of the sounds or not."
"What purpose is served by being able to recall a distressing occasion that we would rather forget, better than the facts that we need to learn for an exam?"