The story
From memory + hole. Sense 1 (“figurative place to which information is deliberately sent to be forgotten, or to which forgotten or lost information ends up”) is a transferred use of the physical slots which the English writer George Orwell (1903–1950) refers to in his novel Nineteen Eighty-Four (1949), into which censored documents for destruction are dropped.
Etymology from Wiktionary, CC BY-SA 4.0.