I want to persuade you that when you have a memory, you don’t retrieve something that already exists, fully formed—you create something new. Memory is about the present as much as it is about the past. A memory is made in the moment, and collapses back into its constituent elements as soon as it is no longer required. Remembering happens in the present tense. It requires the precise coordination of a suite of cognitive processes, shared among many other mental functions and distributed across different regions of the brain. This is how Schacter, one of the pioneers of the approach, sums it up:
We now know that we do not record our experiences the way a camera records them. Our memories work differently. We extract key elements from our experiences and store them. We then re-create or reconstruct our experiences rather than retrieve copies of them. Sometimes, in the process of reconstructing we add on feelings, beliefs, or even knowledge we obtained after the experience. In other words, we bias our memories of the past by attributing them emotions or knowledge we acquired after the event.
Fernyhough, Charles. Pieces of Light. HarperCollins, 2012. p. 7