We all have a collective set of memories, your first day at school, the smell of your Mums cooking, to where you were when a significant world event occurred- all of these are what make us who we are.
Do you remember what you had for your lunch yesterday? An image of a chicken sandwich comes to mind for me.
I didn’t have to go through all my memory files for this image to appear, it is stored in a very complex network of creating, recalling and storing groups. These networks all work together to ensure that the image of my chicken sandwich from yesterday appears very easily.
This brain wide process is very complicated and science still doesn’t fully know how the brain organises memory.