I never understood what people mean when they say they become "numb." When I'm happy or content I'm just existing in a calm state. With the more stressful emotions such as fear or anger I do have a physical reaction ranging from increased pulse, headaches, lack of appetite and an inability to concentrate or focus on things. I think this is what naturally happens to most people when under stress which is very strange to me as I didn't have such strong physical reactions to stress when I was younger.