It’s fitting that one of the most important things you can do as a parent requires you to think about something that’s very nearly impossible for a parent to consider. It comes to us from Marcus Aurelius by way of Epictetus.

As you kiss your son good night, says Epictetus, whisper to yourself, “He may be dead in the morning.” Don’t tempt fate, you say. By talking about a natural event? Is fate tempted when we speak of grain being reaped?

No one wants to think about that. You want to think only good things about your kids. Damn these philosophers and their silly, academic exercises. Except that’s not what this is. Marcus wasn’t speaking flippantly. He lost nine children. Nine! Seneca, we gather, lost one early too. It should never happen, but it does. It heartbreakingly-world-wreckingly-nobody-deserves-it does.

The point of thinking about this unthinkable thing is not morbidity. It has a purpose. A parent who faces the fact that they can lose a child at any moment is a parent who dares not waste a moment. A wise parent looks at the cruel world and says, “I know what you can do to my family in the future, but for the moment you’ve spared me. I will not take that for granted.” That’s what you must do—about your children, about your wealth, about peace in your nation, about the fair weather.

It can all go away in a second. There’s nothing we can do about that. We can, however, drink in the present and be grateful for every waking moment.