The antonyms for the phrase "was up about" include "was down about," "was sad about," "was disappointed with," and "was discouraged with." These phrases indicate feelings of dejection or dissatisfaction, rather than excitement or enthusiasm. When someone is "up about" something, they are typically cheerful, hopeful, or excited about a particular topic. Conversely, when someone is "down about" something, they are typically feeling low or defeated. It's important to recognize these opposing emotions and respond appropriately, whether by offering encouragement or assistance, or simply acknowledging and empathizing with the other's feelings.