First thing which came to mind was addiction. Dependency on their drug of choice. Gollum and the Ring, for example.
Or perhaps a person with an illness or injury who gets the chance to heal struggling with the fact they'd come to terms with being this way their whole life. In a way, they were dependent on the idea that they were ill or crippled as part of their identity. Fernando, the paraplegic character in the Netflix original 3%, had this exact issue.