This is a profound moment in what it means to be human, the point at which we start to be able to remember events in our lives, the threads of our life history. This, our autobiographical memory, is quite a different thing from our ability to learn facts, such as that London is the capital of Great Britain. But although at age five, you might have this sophisticated ability, the hardware of your memory is still only partly formed. Its development carries on throughout childhood, something we take so much for granted that it's hard to imagine life without it.