It is a simple fact that nothing lasts - everything is constantly coming, going, and changing. This is something that can be seen intellectually, relatively easily. In meditation, we get the chance to see it in a very direct, experiential way.
Being alive means being in motion. The sensations of the body, the sounds around us, the thoughts and feelings that come and go — all of it is part of a continuous, shifting stream. The mind, which is itself part of this flow, tends to draw boundaries around things. It names them, labels them, sorts them into “me” and “not me”, “inside” and “outside”.
Meditation offers us a way to stay close to experience as it actually is — moment by moment — before the mind organizes it into something fixed. As we tune into the immediacy of change, we may start to relate to it differently. With less grasping, less need to control or take ownership, and more ease.