Where do we store our memories? Does a particular nook or corner in our brains keep our treasured past safe so we can retrieve pieces of it when needed, the way we recover something from a basement room or a dusty attic? Well, not exactly. The brain simply does not have room to store everything we encounter in life. Instead memories get broken up into bits and pieces and, according to a peculiar housekeeping system, are dispersed among the rooms, closets and hallways of the brain. How we get the pieces to fit back together to produce memory is one of the brain's greatest mysteries.

• David Suzuki