Nothing stays the same.
For Planck second to Planck second (10 to minus 43rd of a second) the universe stops and starts again. Planck spoke of the quantum nature of reality. Everything occurs in discrete units (quanta) of existence.
Buddha and Heraclitus saw the apparent flow of a river as an illusion. Discrete (though imperceptible to the human brain) episodes follow from one to the other.
Reality is like a movie. Individual frames when run together at a discrete speed offer the illusion of continuity.
And so with our own lives. We believe we are the same people who began to read this particular blog posting. Yet we are not. Philosophically, metaphysically, biologically we are different. Our bodies have changed. Our thoughts are different. Our chemical processes have continued unabated. We have aged. We are that much closer to our own nonexistence or death.
Buddhists speak of impermanence as a way of providing understanding to all sentient beings.
Their purpose was not to increase our sense of futility or promote existential angst. On the contrary, Buddha believed that by sweeping aside the veils of illusion and forcing us to confront reality, we would be more tolerant of the inevitability of change and impermanence. Such an awareness would lead us to reduce our suffering and seek to attain its release. The result would be liberation from suffering, attaining Buddha-nature, reaching nirvana.
Is that so? Does knowledge and awareness lead to less suffering or to more?
I suppose it depends on the individual. If we can come to terms with reality we should be better able to accept it when it comes our way. But there are many among us who will find this impossible. Their suffering will not be lessened with increased awareness. It might even be exacerbated.
But we do have a choice. We can meditate on the nature of existence. We can accepte what we cannot change with equanimity and serenity.
To achieve this level of awareness brings great healing.