This compelling program explores the extraordinary nature of memory through the stories of people who yearn to remember or long to forget. Case studies and interviews with experts, supported by computer graphics, throw light on the mechanics of implicit and explicit memory, savant syndrome, traumatic memory, flashbacks, "flashbulb memories" such as the space shuttle Challenger explosion, mistaken identification, and memories twisted or even totally invented through suggestion. The effects of short-term memory damage, trauma-induced amnesia, and Alzheimer’s disease are investigated as well. A Discovery Channel Production. (53 minutes)