Fidel Castro spent six hours presenting a two-volume memoir to an audience at a Havana convention center, state media said Saturday. It was a rare appearance for the retired and increasingly reclusive former Cuban leader.Images on state television showed a smiling, animated Castro wearing a dark track suit over a blue plaid button-up shirt.Audio of him speaking was not broadcast, but Communist Party newspaper Granma said he told attendees Friday that they would hear about "two books that you haven't had any news of."Granma said the two-tome memoir, "Guerrilla of Time," fills nearly 1,000 pages and covers Castro's life from childhood until December 1958, the eve of the triumph of the Cuban Revolution. It is based on interviews with journalist Katiuska Blanco."I have to take advantage now, because memory fades," Granma quoted Castro as saying.