To put it into perspective: on average most of us can recall between five and nine numbers in a row. The eight-times world memory champion Dominic O'Brien, 50, can remember the order of 54 randomly shuffled decks of playing cards - an astounding 2,808 cards. He has turned his memory into a full-time career, running memory workshops and writing numerous books.
The event itself is like an intense exam. This year 26 people will take part. The room is silent; one competitor paints his glasses black, leaving a 1cm hole in the middle, to "cut out peripheral vision"; others wear eardefenders to keep disturbances to a