An explanation of how we remember
One popular theory of how we remember was proposed by Richard Atkinson and Richard Shiffrin in 1968. It proposed that the human memory is divided into 3 main sections:
Information from our environment, such as visual images from the eyes and sound, smell, etc. enter the memory here. The information that enters here may only stay here until it 'decays' and is forgotten. But if you pay particular attention to a piece of information - for example, you're focusing on an object or listening to somebody speak - the information will be passed into the second 'part' of our memory...