The ironic work, created in the Leake Street Tunnel, portrays a man, most likely a city worker, who appears to be cleaning a wall covered with some prehistoric drawings. The immediate reaction of every spectator is one of shock and horror, as this maintenance worker, without realizing it, is erasing these precious prehistoric graffiti. Comparing graffiti with ancient prehistoric rock painting, Banksy questions the value society attaches to works of art. The work underlines how much art is often destroyed by those who do not understand it. Memory loss is the most serious form of giving up knowledge.