An explanation of how we remember
One popular theory of how we remember was put forward by Atkinson and Shiffrin in 1969. It proposed that the human memory is divided into 3 main sections:
Information from around us such as visual images from the eyes and sound, smell, etc enter the memory system 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...