What are strong memories made of? Why do we remember what we remember and which memories last, quite literally, a lifetime while others just fade away? In this Brainwaves special Pennie Latin investigates how our brain makes and retrieves memories; explores how memory changes over time and why we seem to remember certain stages of our lives and particular events more sharply than others and considers the memories which remain most precious as we age. Part of the BBC Scotland Memories and Conversations - New Approaches to Dementia season.