Why a pencil has an eraser

The pencil has an eraser because it has a lead, like how positive has negative, right has left and life has death. An eraser, a simple tool that can nullify the dangerous creations of the human mind from reality, an eraser is there to destroy an outcome caused by the lead, it's simply the plan B, or what helps you move to plan B. A rather devastating monster than a dictator who once ruled a portion of our world, and how did we get rid of him, by erasing him from reality, every creation can be destructed, and it's pretty interesting that how even a simple tool like a pencil holds the story of creation and destruction.