According to the Relief Theory, humor is the feeling of relief that comes from the removal of restraint. When tension is high, we need a release, and laughter is the way of cleansing our system of the built-up tension. For example,people often laugh after a scary experience such as a roller-coaster ride or rough airplane landing. This theory explains why humor can help people cope with stressful situations.
Regardless of the theory, in order to be able to appreciate a situation or joke as funny, some detachment is always necessary; that is, we have to feel uninvolved with the situation. for example, we can often laugh at our own past mistakes because, with the passage of time, we have become detached Conversely, if the joke or situation is too familiar or realistic it ma evoke feelings of sadness and concern instead of ones of cheerfulness