So, what were you doing on 2 December, 2003? Can't remember? Apparently we're only a few years away from the cost of data storage dropping so far that we can record "everything" that happens to us: our location at any given time, what we are seeing, and what we are saying or doing. Collectively we're on the edge of losing the ability to forget, says UK science fiction writer Charles Stross. He posits a future in which all human experience is recorded on devices the size of a grain of sand.