Can you remember what you were doing on 15 March 2003? Or what the weather was like on 30 May 2007?
Twenty-year-old British student Aurelien can. He is one of just a handful of people in the world who are baffling scientists with their ability to recall an incredible amount of their lives.
Some claim they can remember every day as if it were yesterday. Now Aurelien is the first Briton to go public with this extraordinary talent. Is it an elaborate trick or some sort of obsessive compulsive behaviour, or perhaps the result of physical differences in their brains?
Aurelien is put to the test by eight-time world memory champion Dominic O'Brien, and examined by memory expert Professor Giuliana Mazzoni.
This remarkable documentary explores the recently discovered phenomenon known as superior autobiographical memory.
It looks into the theories of scientists trying to unravel the mystery in the UK and US, and the lives of the seemingly ordinary people who appear to have an extraordinary power we had no idea humans could possess.
For the experts racing to find the answers, the discovery of this new group of people could transform the way we look at the workings of memory.
Perhaps we all have the same infinite memory system and we just need to work out how to unlock it. But if we could have an almost endless memory, would we really want it?
American school administrator Jill Price was the first person in the world to be discovered with the condition and gives her first interview in over a year. Jill provides an insight into just how difficult life can be for some people when they can't forget.