Buddhist teacher Pema Chodron writes in The Places That Scare You: a Guide to Fearlessness in Difficult Times (2017):

When I first heard this teaching it seemed academic and remote. But when I was encouraged to pay attention – to be curious about what was happening with my body and my mind – something shifted. I could observe from my own experience that nothing is static. My moods are continuously shifting like the weather. I am definitely not in control of what thoughts or emotions are going to arise, nor can I halt their flow. Stillness is followed by movement, movement flows back into stillness. Even the most persistent physical pain, when I pay attention to it, changes like the tides.

I feel gratitude to the Buddha for pointing out that what we struggle against all our lives can be acknowledged as ordinary experience. Life does continually go up and down. People and situations are unpredictable and so is everything else. Everybody knows the pain of getting what we don’t want: saints, sinners, winners, losers. I feel gratitude that someone saw the truth and pointed out that we don’t suffer this kind of pain because of our personal inability to get things right.

That nothing is static or fixed, that all is fleeting and impermanent, is the first mark of existence. It is the ordinary state of affairs. Everything is in process. Everything – every tree, every blade of grass, all the animals, insects, human beings, buildings, the animate and the inanimate – is always changing, moment to moment. We don’t have to be mystics or physicists to know this. yet at the level of personal experience, we resist this basic fact. It means that life isn’t always going to go our way. It means there’s loss as well as gain. And we don’t like that…

We know that all is impermanent; we know that everything wears out. Although we can buy this truth intellectually, emotionally we have a deep-rooted aversion to it. We want permanence; we expect permanence. Our natural tendency is to seek security; we believe we can find it. We experience impermanence at the everyday level as frustration. We use our daily activity as a shield against the fundamental ambiguity of our situation, expending tremendous energy trying to ward off impermanence and death. We don’t like it that our bodies change shape. We don’t like it that we age. We are afraid of wrinkles and sagging skin. We use health products as if we actually believe that our skin, our hair, our eyes and teeth, might somehow miraculously escape the truth of impermanence.

The Buddhist teachings aspire to set us free from this limited way of relating. They encourage us to relax gradually and wholeheartedly into the ordinary and obvious truth of change. Acknowledging this truth doesn’t mean that we’re looking on the dark side. What it means is that we begin to understand that we’re not the only one who can’t keep it all together. We no longer believe that there are people who have managed to avoid uncertainty.