The phrase “you keep me sane” expresses gratitude or appreciation towards someone for providing emotional support, stability, or comfort during challenging times. It suggests that the person’s presence, actions, or words help the speaker maintain their mental health and well-being. Essentially, it conveys that the individual plays a crucial role in helping the speaker cope with stress, anxiety, or difficult situations, preventing them from feeling overwhelmed or losing control. This sentiment often reflects a deep connection and reliance on the other person in the context of friendship, family, or romantic relationships.