Imagine being able to recall every detail of your life like it happened yesterday - what you wore, the weather, what you ate.
A very small part of the population can indeed do just that without the use of any mnemonic devices or memory enhancement drugs. For better or worse, people with Hyperthymesia or Highly Superior Autobiographical Memory (HSAM) can remember details of their everyday lives in extraordinary detail from decades ago, while other types of memory decay normally.
Here's a short video of Marili Henner demonstrating this ability: People who remember every second of their life | 60 Minutes Australia - YouTube