One of the key, frequent, things in life is having to deal with disappointment. And consequently a lot of our suffering comes from this area, as like this first quote says. We prefer to rerun the memory of an event or a feeling or some words, rather like a dog returning to a bone. A wiser way of acting is suggested in the second quote, staying as close as possible to the felt sense of the experience, thus limiting it spinning off into a reactive cycle of thoughts and emotions.
Disappointment has a chimerical quality because our minds refuse to accept what is; therefore, we relive the disappointment over and over again, never noticing after the initial experience that it is only a memory we are re-experiencing, much like watching old movie reruns.
If you can stay present when something disappointing occurs, the next response is to open fully to the experience. Don’t deny it, don’t push it away, but realize, “Ah, this is disappointment. What does it taste like? Where is it in my body? Is the feeling expanding or contracting?” Open to the experience of disappointment so that you can accept it and let it pass through your mind and heart. Then you can go on with your life’s journey and not be frozen in place by your pain.
Philip Moffitt, Living with Disappointment
Our practice is not to shut everything out; it’s to remain conscious of our environment and what’s happening in it. Then we can deal with it appropriately. We can open the door to our angry thought, listen to it, and then ask it to leave. We recognize it as a thought and don’t mistake it for who we are. That’s the point. It shifts the experience. Instead of thinking, “I’m really angry right now,” we think, “Oh, look, an angry thought has entered my mind.” It’s easy to let go of a thought that’s a guest in your mind; it’s harder when you take on the identity of the guest. 
Emotions are mixes of “felt senses” and activities. Witnessing them is helped by the simple fact that the body resonates with the moods and impulses that run through it. (When we’re angry we tense up and the heartbeat changes; when we’re loving and joyful, the body feels vibrant and so on). This resonance gives us a way of addressing the heart by addressing the bodily aspect, of steadying or relaxing the emotion by grounding attention in the body and simply breathing. 
Mindfulbalance 