Kim Jungsu ‘It-hyeojin Gyejeol(the Forgotten Season)’ is the title of a popular song. ‘It-hyeojin’ means that: I did not want to forget. Passing time made me forget the season. Therefore it is more appropriate “The season was forgotten by passing time” rather “The season was forgotten by me.” ‘It-hyeojin’ is not double passive but passive voice of causative verb. And its meanig is not ‘be gorgotten’ but ‘make be gorgotten’ in English. ‘It-hyeojin Gyejeol’ has Educational Implications. First, teachers and student can explore together why the wrong expression is widely used. Second, it is possible to describe that ‘It-hyeojin Gyejeol’ is grammatically correct expression. And expand the contents of grammar education in Korean education. Thirdly, teachers can lead students to use Korean language creatively. The expression used in the literature can be analyzed more accurately by this proposal.