In everyone’s life there are unpleasant experiences. This is an inescapable truth of life. In Buddhist terms we call this Loka Dhamma, which literally means truth of the world. The Buddha identified four pairs of Loka Dhamma. These are gain and loss, fame and obscurity, pleasure and pain, praise and blame.
If we consider our lives through the prism of these four pairs, we can see that we are constantly alternating between their various elements. This is a natural truth of the world. There is no point, therefore, in arbitrarily signaling out one particular instance to attach on to and worry about. Instead, we can simply become aware of how our experience fluctuates over time.
This technique, where we direct the mind to observe the arising and passing away of phenomena over time is called Vipassana mediation which we often translate as insight meditation. It works because observation of what is happening can only occur in the present moment.
When we observe how things are changing, this necessarily brings the mind away from dwelling on an unpleasant experience of the past or some irrational worry about the future. The mind, when trained in this way, can finally be at ease.