Memory is one of those things that doesn't work the same way in a computer and in a human brain. Memory in computers is like having millions of 'yes or no' switches that stay the way you set them.
Memories in a human brain are not set in stone; they become actively integrated with your thinking processes. Remembering works by being and doing, not by simply retrieving data from a memory bank.
From a psychic's point of view, the brain is good at converting the past into the NOW. There are so many sensations, experiences and revelations we go through every day and every moment - and it's all NOW.
What is interesting is that process is not limited to the past; it also applies to the future. A psychic uses 'forward remembering' or 'forward memory' to see and realize the future. The same way past is brought into the NOW, so is the future.
All forms of psychic energy are the consciousness of such memory processes. A psychic who digs deep enough and uses the brain as a filter and a gateway can access memories that have not originated from his or her bodily experiences - but from anywhere within the universe.