The comfort zone is that psychological space in which one feels secure, safe and at ease. Why would anyone want to leave their comfort zone? Who wants to be uncomfortable?
Well, one motivation is to be more effective and happier; to perform optimally. In conventional thinking there is an optimal performance zone that is outside of the comfort zone. There is also a zone of impaired performance that is entered when the level of stress becomes too high. The goal of achieving and sustaining optimal performance motivates people to learn to be ready to confront and manage change and work well under stress.