It’s easy to nod along with a book (or even this email) when you’re reading it. Or to double-tap the like button when you see an inspiring Instagram post.

But how long does this stay with you? How quickly will its message flutter away? It’s a critical problem for all of us out there who are trying to get better. Who are trying to actually live the principles of philosophy, and to rely on it in life’s stressful moments, as well as life’s ordinary hours.

Stoicism as a philosophy was made to be kept in hand, always at the ready. Even the title of Epictetus’s Enchiridion (hand book) shows this. As A.A. Long writes in his recent translation of Epictetus for the Princeton University Press:

In its earliest usage Enchiridion refers to a hand-knife or dagger. Arrian may have wished to suggest that connotation of the work’s defensive or protective function. It fits his admonition at the beginning and end of the text to keep Epictetus’s message “to hand” (procheiron).

That really tells you something about this philosophy, doesn’t it? That it’s not just a book, it’s not just handy; it’s designed to become almost like an extension of ourselves. To protect and serve us in each day’s tests.

When it comes to memento mori (“remember you will die”), different generations have attempted to keep this idea at hand in different ways. The result can be seen across generations of writing, art, music, jewelry and ritual.

Roman generals employed aides to remind them of this fact at their moments of greatest triumph. Philosophers have kept skulls on their desks for millennia. In early Buddhist texts, a prominent term is maraṇasati, which translates as “remember death.” Some Sufis have been called the “people of the graves” because of their practice of frequenting graveyards to ponder on death and one’s mortality. In Renaissance Europe, memento mori prayer beads were a popular way to keep death in mind. Famous artists from Rembrandt to Damien Hirst have added to the memento mori genre, centuries apart from each other. Beneath the church of Santa Maria della Concezione dei Cappuccini in Rome, there is a crypt built in 1630, decorated with the remains of 4,000 friars. In the middle, there is a plaque inscribed in three different languages that states, “What you are now, we once were; what we are now, you shall be.”

They all were trying to remember: We can go at any moment.

While times change and it may no longer be practical to keep an aide to whisper death in your ear, the benefits of memento mori remain.