You shouldn't be over-critical of your partner.
Janet has been forgetful lately due to a new medication and has forgotten to pack Jim's lunch.
Jim wants to express the importance of his lunch to Janet.
Jim expresses understanding of Janet's struggles and asks if she can work harder to remember the lunch.
Jim gets angry and yells at Janet, calling her incompetent.
Janet takes steps to remember things like lunches more.
Janet tells Jim that she doesn't want to remain in a relationship with him.