Stillness Is the Key by Ryan Holiday

Memento mori.
This is a fact that, perhaps more than anything else, is responsible
for incredible amounts of anxiety and distress. It’s scary to think that
we will die. As is the fact that we cannot know for certain what will
happen when death comes, whenever that is. Is there such a thing as
heaven? Or hell? Is death painful? Is it nothingness, a dark backward
abysm of time?
Seneca reminded himself that before we were born we were still
and at peace, and so we will be once again after we die. A light loses
nothing by being extinguished, he said, it just goes back to how it was
before.
The denial of this simple, humbling reality—the denial of death—
is why we attempt to build monuments to our own greatness, it’s why
we worry and argue so much, why we chase pleasure and money and
cannot be still while we are alive. It’s ironic that we spend so much of
our precious time on earth either impotently fighting death or futilely
attempting to ignore the thought of it.
It was Cicero who said that to study philosophy is to learn how to
die.
Most of this book has been about how to live well. But in so doing,
it is also about how to die well. Because they are the same thing.
Death is where the three domains we have studied in these pages
come together.
We must learn to think rationally and clearly about our own fate.
We must find spiritual meaning and goodness while we are alive.
We must treat the vessel we inhabit on this planet well—or we
will be forced to abandon it early.
Death brings an end to everything, to our minds, our souls, and
our bodies, in a final, permanent stillness.
So we end this book there as well.