Impermanence (anicca) is one of the three marks of existence in Buddhist teaching and a cornerstone of the Buddha's path to liberation from suffering.
How to Practice
Sit quietly and observe your surroundings
Look at the room around you, the light, the sounds. Notice that everything you see is in some stage of change, however slow.
Bring to mind something that has changed
A relationship, your body, a phase of life. Recall how different things were a year ago, five years ago. Let the reality of change settle.
Notice something changing right now
Your breath rises and falls. Sounds appear and disappear. Light shifts. Even your thoughts are constantly moving. Nothing stays still.
Rest in the awareness of change
Instead of resisting impermanence, let it become a source of comfort. This moment is precious precisely because it will not last.