Recent L2 motivation research has paid attention to the dynamic nature of motivation and to the process of motivational changes in L2 learning. While studies have mostly focused on the factors positively influencing L2 motivation, relatively little research has been conducted on the factors that influence learner demotivation. In this light, the study examined the factors affecting Korean college students’ demotivation and their reaction to demotivation by drawing on the notions of ideal L2 self and ought-to L2 self in Dörnyei (2005, 2009). Based on interviews with twenty-nine Korean college students, three factors were identified as demotivating factors: lack of meaningful purpose, lack of improvement and success experiences, and lack of self-determination. It was noted that the conflict between the students’ desire to use English for communication and the immediate need to gain good scores on standardized tests was the main source of learner demotivation. However, the students with a strong ideal L2 self were more successful in setting personalized goals and participating in personally meaningful activities when demotivating factors were present. The findings indicate the importance of learners’ ability to visualize their ideal L2 self in overcoming demotivation and remotivating themselves.