The great Richard Feynman said that if someone can't explain something simply to a novice — at the freshman lecture level — it's because they don't actually understand it themselves. This is not only a true statement but it's also passing indictment of most of academia. I would argue that it also happens to indict most of what's described as of "philosophy" today. Something like physics is complicated by nature of that fact that it often requires the understandings of several other fields to get right. Feynman would have trouble explaining quantum physics without also explaining how probability theory works.

But philosophy?

It was never supposed to be that complicated. Philosophy is simply one thing: a guide to the good life. No more, no less.

One philosophy that's popular right now is Stoicism, an ancient school of philosophy which dates back to Greece in the 3rd Century BC. Today, football coaches like Pete Carroll of the Seattle Seahawks, baseball managers like Jeff Banister of the Texas Rangers and investors like Tim Ferriss have all talked about and used Stoicism (it's been popular in the past too — with fans like Theodore Roosevelt, Frederick the Great and Montaigne). In the last few weeks alone, there have been articles about Stoicism in the New York Times, the Wall Street Journal, the Financial Times, the Guardian, the New Yorker and ESPN.

But, what is Stocism? Is it complicated and boring like most philosophy? Does it have any real application for ordinary people's lives or is it just a bunch of big words and silly theories?

Someone recently asked me to explain Stoicism to them like they were 5 years old. While this exceeds even Feynman's standard, I think this is not only possible, but an essential task. So here it goes.

First, if I was sitting down with a five year old, trying to teach them the ethos of an ancient philosophy, I don't think I would explain it as Stoicism or as "philosophy." What use does a five year old have for the concept of philosophy — or really any "concept" at all? They don't need to know the name, the dates or even the major figures like Seneca or Marcus Aurelius or Epictetus. Not only are these things confusing, they are inessential. In the same way, a kid doesn't need you to explain how dinner was made to eat the food on their plate — they just need your help getting it there.

If I was trying to explain Stoicism to a five year old, I would simply try to convey the most essential piece of wisdom contained inside this robust, complex topic.*

I'd tell them: "Look, you don't control what happens to you in life, you only control how you respond."

They'd probably say, what do you mean?

So I'd say: Remember when your friend was mean to you last week? Remember how that surprised and hurt you? What they did wasn't nice of them, but there also wasn't anything you could do about it. If someone wants to be mean, they're going to be mean. But after they were mean, you had a choice. Remember? You got to decide whether you were going to be mean back, whether you were going to hit them, whether you were going to run to the teacher and tell on them, or whether you were going to just keep playing and forget about it. You have a choice about whether you're going to forgive them or stay mad and hurt about it. The fact that you've let go? That was a great decision you made.

Or I'd say: Remember how it was raining earlier and you couldn't go outside. Remember how you were grouchy about it and just looked out the window because you didn't get to go to park? That was a choice too. The weather — that just happens. Sometimes it means we're stuck indoors. But we choose what we do with that time. You could have cleaned up your room or played a game or helped your mom with some chores or you could have sat there and watched the rain on the windows without throwing yourself a pity party.

I know that seems really simple, but it isn't. That situation I just described — when someone does something bad to you and you have to decide how to respond or when the rain comes and wrecks your plans — well, that's life. Adults struggle with it. Even your parents don't always get it right.

I'd tell them that many thousands of years ago, another famous guy struggled to get it right. That guy's name was Marcus and he was the king of Rome. He had unlimited power — he could do whatever he wanted — but he still worked really hard to be a good person and tried to never get mad, do something unfair, to be selfish, or to think he was better than other people. I'd say: Isn't that inspiring? Can we try to follow his example?

If he was following along, I might share with him a little prayer that, while it wasn't actually created by the Stoics, describes their way of thinking pretty well. I'd say, I want you to repeat after me, and then I'd say the Serenity Prayer:

>God, grant me the serenity to accept the things I cannot change,



Courage to change the things I can,



And wisdom to know the difference.

I'd ask, Do you know what all those words mean? I wouldn't assume they would. But explaining would be really simple: Serenity means peace and acceptance — like, you know, when you're tucked into bed and you stay there, even if you want to stay up. Courage is bravery — when you go do something even though you're scared, because you know it's the right thing to do. Wisdom — you know what wisdom is — that's when you can see things clearly, not like a kid but like grandma or grandpa can, how they know just what to say or do in every situation.

I'd point out that really what the Stoics were saying with that prayer is that we have to know the difference between what's in our control and what isn't. We have to focus all our energy on what we can control and be OK with the stuff that isn't. You're little right now, so you're probably used to stuff not being in your control. Your parents tell you what to do. Your body gets tired. You can't do a lot of stuff on your own. That might make you mad, but it's also part of life. But there are also so many things that are in your control. Whether you smile — that's in your control. Whether you tell the truth — that's all you, buddy. Even a lot of the stuff your parents "make" you do, they aren't physically forcing you do. It's on you to either do it, or face a punishment. Yet there's still a choice.

What would be essential to explain to this little kid is that the better we can get understanding the difference between what's in our control and what isn't, the happier we'll be and the more fun we'll have and the less sad we'll be. The better our life will be.

I'd make sure they knew that I wasn't trying to tell them that they have no control over their life. On the contrary, I'd want them to know they actually a lot. I'd say that I want you to know you're really powerful. You're as powerful at that king was and as powerful as soldiers and heroes and big strong adults are. Why? Because you get to choose how you respond to everything. You get to choose whether you're mean or nice back to someone whose mean to you. You get to choose what you do when it's raining—and how much fun you have whatever the weather happens to be.

If you can learn that now and embrace it, you'll have the best life ever and no one will ever be able to boss you around. Because you'll be the real boss. The boss of your thoughts, feelings and decisions.

At this point, I'd start to wrap up. I'd say that basically, that's what Stoicism is — and hopefully you can see why some of your sports heroes and the brave men and women we've read about in books have followed it. Of course, there's a lot more to it and I can't wait to tell you all of it as you get older.

But for now? What I just gave you is a lot. Enough that even a lot of adults haven't totally figured out. So if you can even start to get the hang of it now, at 5 years, old, everyone would be so proud of you.

*Of course, if you're an actual adult and you want to learn more about the Stoics, you can read the originals like Seneca or Epictetus. Or I've put together a seven day introduction to Stoicism which you can try as well.

Ryan Holiday is the best-selling author of The Daily Stoic: 366 Meditations on Wisdom, Perseverance, and the Art of Living. He is an editor-at-large for the Observer, and you can subscribe to his posts via email. He lives in Austin, Texas.