“One person likes tending to his farm, another to his horse; I like to daily monitor my self-improvement.” — Epictetus, Discourses, III.5.14

Seneca opens one of his letters saying he’d just gotten back from attending the lecture of a philosopher from a different school. He anticipates the question his friend Lucilius will probably have: aren’t you a little old to still be attending philosophy classes?

Seneca says there is nothing “more foolish than refusing to learn.” Even in old age, even if you haven’t had to learn for some time now, even if you are one of the best at what you do — “you should keep learning…to the end of your life.”

As we talked about a couple of days ago, the Stoics prized nothing more than wisdom. They said part of being a philosopher is committing to being a lifelong learner. One of the reasons, what Seneca goes on to explain to Lucilius, is that wisdom is one of the few certainties in life in the sense that it is one of the few areas of growth we have control of.

Money is nice, Seneca admits, but making more and more of it is largely a matter of luck. Titles, influence, authority, admiration—again, these are great but for the most part, they’re out of our control. But wisdom, learning, studying, Seneca says, do not fall upon us by chance. “‘How much progress shall I make?’ you ask. Just as much as you try to make. Why do you wait? Wisdom comes haphazard to no man.”

Seneca of course was not the only Stoic continuing to learn all the way until the end of his life. Marcus Aurelius was forty when he became emperor. Well into his reign, we learn, he was attending the lectures of a philosopher named Sextus. People sneered at him. Didn’t the emperor have more important matters to attend to? And besides, didn’t he already have the philosopher on his staff? And, didn’t most of Rome already celebrate his greatness, his great mind? Why was he going out of his way to sit in Sextus’ classroom? “Learning is a good thing,” Marcus replied to one detractor. “Even for one who is growing old. From Sextus the philosopher I shall learn what I do not yet know.”

You have not graduated. School is not out for winter break. You are not too old or too good at what you do. No, school is life. Learning is a daily thing. Wisdom is a lifelong pursuit. You must never stop studying, learning, growing. There is nothing more foolish than giving those things up. So today’s challenge will hopefully become a lifelong habit. Every day, you should try to learn something new. Every day, you should read or watch something about a topic you know nothing about. And you should start today. Why wait?

It should be obvious to you by this point. The next few months and years are going to be rough. We don’t know exactly how rough, but certainly, considerably rougher than last year. That’s not yours to control or prevent. What’s up to you is how ready you will be. It’s in times of peace that a nation must sharpen their swords. And it’s in times of a lockdown that you must sharpen yours.

Regardless of what the future holds, now is the time to get ready. To use this moment, to prepare, to sharpen, to learn what you do not yet know.

Read about other philosophical schools. Read about psychology or physics or architecture or agriculture or nutrition or human nature or crypto or artificial intelligence or law or economics. Read about a culture you know nothing about or a part of the world you’ve never been to. Watch a Ken Burns documentary about The Civil War or The Vietnam War or national parks or jazz or baseball. Watch a TED talk on YouTube about body language or bionics or shame or quadcopters or cave symbols.

You may be thinking that making time to learn something new, to attend classes seemingly unrelated to your profession, seems selfish when there’s people relying on you. But it isn’t selfish. It’s selfless. You know what happens when you’re learning and growing too? Everyone around you grows too. Remember what we talked about on day 6? We humans can’t help but have the character of those around us rub off on us. When you become more well-rounded, a more complete person and citizen, everyone in your vicinity does too.

And yes, it is a little bit selfish:

• On a physiological level, learning new things is good for your brain. According to Behavioral and Systems Neuroscientist Tracey J. Shors, learning new skills bolsters cognitive functioning. Learning sparks a process called neurogenesis, or the creation of new brain cells, keeping the brain healthy and active, which is particularly important as we age.

• According to positive psychologist Mihály Csíkszentmihályi, in our brains, happiness and learning are tied together. Best known for coining the psychological concept of flow in his seminal work Flow: The Psychology Of Optimal Experience, Csíkszentmihályi says of learning new things: “the best moments in our lives, are not the passive, receptive, relaxing times…The best moments usually occur when a person’s body or mind is stretched to its limits in a voluntary effort to accomplish something difficult and worthwhile.”

And as Robert Greene talks about in Mastery, learning and personal growth are necessary and positive endeavors. “You must convince yourself,” he writes, “people get the mind and quality of brain that they deserve through their actions. Despite the popularity of genetic explanations for our behavior, recent discoveries in neuroscience are overturning long-held beliefs that the brain is genetically hardwired. Scientists are demonstrating the degree to which the brain is actually quite plastic.”

When you learn new things, you create new synaptic pathways. Greene calls it the great salvation. We are heirs to the most ingenious instrument. The miracle device we use to perceive the world can grow and develop infinitely. As you learn something new today, Greene would say, “you are contributing to the most important cause of all—the survival and prosperity of the human race, in a time of stagnation.”

If you’re not constantly learning and improving and adding new skills to your game, what are you doing? You’re stagnant, you’re running on the hamster wheel, you’re in what David Epstein calls the “rut of competence.” We make sure we never find ourselves in one by constantly learning and pursuing new skills. We have to build it into our day. Every day. From now to the end of your life.

Additional Resources:

• The Maxim For Every Successful Person; ‘Always Stay A Student’ by Ryan Holiday
• The Daily Stoic, May 17 — The Stoic Is A Work In Progress
• Bestselling Author David Epstein On Philosophy, Accepting Obstacles, and Why Generalists Triumph in a Specialized World
• Be A Generalist
• It’s Time for Class
• Wisdom is the Most Important Virtue
• To Crush Your Ego, You Must Love Learning (and Books)

*Ryan Holiday audio commentary on Day 13. Click here to listen.

**New Year, New You Full Calendar. Click here to download.

***Miss a day? Day 12, Day 11, Day 10, Day 9, Day 8, Day 7, Day 6, Day 5, Day 4, Day 3, Day 2, Day 1.