Michelangelo
One day the great Italian Renaissance artist Michelangelo happened to overhear a group of people admiring his Pieta, a statue of Christ on His mother's knees after His death on the cross. One man attributed the work to another sculptor, much to the chagrin of Michelangelo, who took particular pride in the Pieta.
Returning to the sculpture after dark that evening, Michelangelo carved his name on it so that no similar mistake would occur in the future.