“The less energy we waste regretting the past or worrying about the future, the more energy we will have for what’s in front of us.”

Amazon tells us that’s one of the most highlighted passages in the digital version of Stillness is the Key.

It’s an idea that’s impossible to disentangle from Stoicism. Epictetus said there were things that were up to us and some things were not. Ok, but then what? Remind yourself, Marcus Aurelius writes in Meditations, that the past and the future are not in our power, only the present is.

You have to try to live in the very now. It is the only thing that exists. And it’s the only thing that is true. Our memories of what’s passed degrade and then betray us. Our thoughts of what is to come are never accurate. Now is all there is and all that is real.

So, Marcus wrote, “give yourself a gift: the present moment.” Live immediately, Seneca wrote. Give yourself a gift: truth and reality. When you do—when you put all of your energy into the present—you can be sure you are using your resources wisely. Free of regret and worry. What a present that is.