Why should a young man listen to an old guy about the best way to become a man? Because the typical teen is not yet able to see a future past the next few months. That's not a fault of character, but the fact that teens' brains have not yet physically matured. The pre-fontal cortex (PFC) does not fully develop in most people until they're twenty-four years old. Yet, the PFC is responsible for regulating mood, attention span, impulse control, and the ability to plan ahead and understand the consequences of one's actions. In the meantime, it's up to the adults to guide them by showing them possible consequences—good and bad—of their behavior. With that in mind, here's my guide to becoming a man:

1. Learn who you are as an individual.

Figuring out who you are, what you care about, what you believe in, and what you stand for is the most important—and most difficult—challenge of becoming a man. We're all raised with people telling us what to think, how to act, and what to say. Sometimes those people are parents, teachers, ministers, and other so-called authorities. Sometimes they are our friends and peers. Most of the time, given the choice, we seek the easiest path, the path of least resistance. We go along to get along. Sometimes that's okay. But it's those instances when you opt for a different path that can really define you as an individual. The important thing is you make those decisions for yourself—not out of spite against authority figures, or because of peer pressure, or even out of fear of losing someone's affection—but out of conviction of who you are and who you want to be.

2. Stand up for yourself and your beliefs.

British statesman Edmund Burke once said, "The only thing necessary for the triumph of evil is for good men to do nothing." That's one of my favorite quotes because it reminds me that it's not enough to have lofty ideals and beliefs, you sometimes have to actually get off the couch and defend those beliefs. This is especially hard when you're hanging with your friends and they all express an opinion that is the opposite of yours. Because you're outnumbered, it's easy for them to ridicule your opinion. Be strong. Defend your opinions and beliefs. If you think it's wrong to be racist but someone in your group says something racist (or sexist, or ant-Semitic, or anti-gay), then tell them you don't agree and that you don't think they should make such statements. That's how these verbal bullies are eventually defeated. More important, you'll feel proud that you took a stand. Those moments you do nothing will haunt you for a long time.

Rogers Photo Archive Getty Images

3. Avoid a physical fight—if you can.

You're probably thinking, "That's easy for you to say, Kareem. You're 7'1" so nobody wants to mess with you." That wasn't always true. When I was a young boy, I was bullied. And my dad was a cop, so that made it even more embarrassing. Later in life, I took up martial arts and even trained with my good friend Bruce Lee. That's why you can trust me when I say that fighting is almost always a mistake. There's a Chinese proverb that says, "The man who throws the first punch has lost the argument." That means that when an argument turns into a fight, it's because the one starting the fight realizes he isn't smart enough to win verbally, so he resorts to violence. It's always the dumbest guy who resorts to violence.

What do you do if someone threatens you with violence? You walk away, even run away if necessary. Even if you're pretty sure you could take him. Bad things can happen in a fight, even if no one means them to. Someone can take an unexpected fall and crack his head open. Teeth can be knocked out. Facial bones can be cracked. And all the crying later about how "it was an accident!" won't change that.

So, if you're threatened, leave and tell your parents. Some people are of the belief that you should just go right after the bully, fighting him to show you're not afraid. While this works well in movies, it doesn't work as well in real life. These days violence tends to beget violence. The bully doesn't just slink away, he returns with a baseball bat—or worse. You can still stand up for yourself without resorting to violence: that's what Gandhi, Martin Luther King, Jr., Cesar Chavez, the Buddha, and Jesus did.

The only time you should fight is if there is no other recourse. You can't run, you can't talk your way out of it. If that's the case, hit first, either in the nose (sometimes the blood will discourage further fighting) or the crotch (because the pain will make it hard for him to chase you). One punch and then run.

4. Play a team sport.

I'm all for individual sports—as I mentioned, I did martial arts for many years and also yoga. (Don't think it's a sport? Try it!) But playing on a team teaches you how to interact with others, adjust to various personalities, work together as a team, be generous, and many other character-building traits. The cool part is that you don't have to join an organized team; you can just go down to the playground or open gym and play pick-up basketball or volleyball.

Robert Abbott Sengstacke Getty Images

5. Choose your friends for the right reasons.

Good friends can see you through a lot of the tough parts of growing up. But bad friends can actually be the cause some of those tough parts. Don't hang out with kids just to piss off your parents or try to be something that you're not. You waste a lot of your youth that way—and miss out of some meaningful friendships.

6. Fight your fear of the unknown.

We all have a tendency to hate what we don't understand, whether it comes in the form of different food, different cultures, or different ideas. There was a Yale study in which researchers examined the brains of people as they were presented with proof that an opinion they held was wrong. MRIs showed that when those people immediately rejected the new evidence, their brains released an addictive chemical that made them feel good. In that way our own bodies are actually encouraging our ignorance and fear. Fight that impulse. Becoming a man means growing, learning, and understanding—not cowering under a blanket with a handful of comforting notions.

(By the way, don't confuse physical bravery with intellectual bravery. It's easier to jump out of a plane—hopefully with a parachute—than it is to change your mind about an opinion. Acts of physical bravado will give you an initial rush, but exploring a new culture or examining a new idea will mature you and make you the kind of person others will be interested in.)

Bob Gomel Getty Images

7. Listen to advice.

Whatever troubles and doubts you're facing, billions of guys before you have gone through the same thing. Your dad probably knows exactly how you feel most of the time because he can remember the same pain and anxiety. Listening to people's advice doesn't always mean taking it. You have to decide which advice is right for you. But it might be a good idea to collect some quotes from those who came before you so you can refer to them when you need to.

I'm going to get you started with one of my favorites from philosopher George Santayana: "Those who cannot remember the past are condemned to repeat it." That means that if you don't learn from the experiences of others and yourself, you will end up making the same mistakes over and over. So, when someone gives you advice, don't dismiss it just because they're older than you.

8. Be politically aware.

One clear difference between children and adults is an awareness of your community outside your circle of friends and family. The world is constantly changing. Whether it changes for the better or the worse depends on the actions of those willing to get involved. Kids who don't know anything about their world try to hide it by saying, "I don't really care. It doesn't affect me." But that just confirms that they wish to remain children and have adults tell them what to do and think. Part of being a man is to be informed so you are prepared to take an active and responsible place in your society. Read newspapers, magazines, watch the news. Discuss these subjects with your friends, but always while respecting each other's opinions.

Don Hogan Charles Getty Images

9. Mind your manners.

When you're a kid being told to firmly shake hands, keep your elbows off the table, or ask guests if they'd like a drink, it all seems like a load of dumb and arbitrary rules. Some of it is. But part of becoming a man is the realization that it doesn't matter whether or not the rules of manners make sense. What matters is the effect of following these rules: people appreciate the effort and respect shown them. In turn, they will show you respect.

Bill Ray Getty Images

10. Be patient in love.

Most of the information boys have about girls is WRONG! WRONG! WRONG! It's based on stereotypes, rumors, bad songs, shallow teen movies, and immature celebrities in personal tailspins. The worst thing you can do in looking to find a significant other is to try to change yourself into something you're not just because you think that's what girls are looking for. It doesn't work.

The best way to get an idea of what's attractive to girls is to talk to them. Like a girl? Get to know her, ask her about herself, then show her you've been listening to what she says. Did she mention a book she likes? Send her an article about the book. It's low-key, non-stalkerish, and shows you care what she talks about.

11. Stay fit.

It's hard for all those teenage boys with turbo-charged metabolisms to understand that their bodies will not always be evaporating the masses of greasy calories they consume. They can eat a pizza and a tub of ice cream, then run three miles. They can't imagine that will ever change, even when you show them photos of their lean dads' as teens and they look at the potbellies that have miraculously appeared later. But eating somewhat healthily and maintaining an exercise regimen will not only help fight off diseases and aging, they'll also help ensure an active lifestyle for many years. In other words, the body is like any machine: It may run great when it's new, but after years of neglect it will slow down, and eventually break down. Then you're the one vegging on the sofa while your pals are playing pick-up ball at the gym.

Bob Gomel Getty Images

12. Never, never do something on a dare.

"I dare you" may be the three most dangerous words in the language for kids. The challenge to prove yourself to others is very tempting, especially since the alternative seems to be showing yourself to be a coward. But that's not really the case. The person who dares you is counting on your not being strong or smart enough to see this challenge as the empty, laughable joke it is. The person who refuses a dare displays intelligence, courage, and independence. And that's what daring someone is trying to rob them of.

13. Get organized.

One main difference between a boy and a man is that boys talk about what they want to do and men actually do those things. Another difference is that men have less time to accomplish more. In order to do all the things they want, they have to be organized. They keep a calendar (the one in your smart phone is handy), they make a to-do list, and they don't put off doing things until later. Being organized can change your life: you do more things you want to do, you finish things you need to finish, and you have more time to pursue new activities and relationships. In general, you will be much more successful.

14. Find heroes to copy.

There are so many worthwhile people to look up to and try to emulate. People from history. Even characters in books and movies. The trick is in picking the right people for the right reasons. Skip most sports, music, and movie/TV celebrities. It's not that they aren't nice people, but the fact that they're successful and make a lot of money doesn't make them wise. Often, it's just the opposite. They pursued fame and glory so single-mindedly that they have no other interests and minimal education. Many are woefully misinformed about current events, yet at the same time frequently offering their weak, misinformed opinions. Don't make the mistake of believing that just because a person can act or sing, he or she also has valuable insights into politics or culture. Find heroes—real or fictional—that embody the values that you want to have, not the bank account.

15. Be independent.

A man can take care of his own daily needs. In fact, he wants to. Make your bed, do your laundry, learn to cook, hang up your clothes. Slovenliness is the sign of an immature mind. The sooner you start doing things for yourself, the sooner you will have the respect of others—and of yourself.

Bill Ray Getty Images

16. Question authority.

Respect your elders but don't think them infallible. Teachers, parents, relatives, politicians, and well-meaning guys like me really do want what's best for you. But we aren't always right. Even when presenting supposed "facts," people can be misleading in an effort to manipulate you into being who they want you to be or doing what they want you to do. History is filled with politicians misrepresenting "facts" in order to convince the population to back rash policies. Teachers sometimes aren't caught up on the latest research. To be your own man, you will have to make up your own mind about things.

17. Get smart.

Making up your own mind doesn't mean "going with your gut," "listening to your heart," or any other such clichés, however. That's the lazy man's way of avoiding the work that comes with developing an informed opinion. Want to express an opinion about the election, the death penalty, or gay marriage? First, do your research. Don't rely on biased sources. Your goal is to find the truth, not just confirm an opinion you already held. Every time you express an uninformed opinion, others will dismiss you as a child, someone who can only parrot others' opinions. A man knows how to educate himself in pursuit of truth.

Bill Ray Getty Images

18. Express yourself.

Go ahead, dye your hair purple. Grow it long, shave it off. Wear all black, wear all white, wear boots, wear leather, wear a dress. This is the time to try on new identities to see which ones fit you best. Sure, you might have to endure some taunts, but it's more important that you figure out who you are than caring what those shut-ins of the mind think.

(A word of caution: avoid doing anything permanent, like tattoos, because, just your taste in clothes, hair styles, music, your thoughts about pretty much everything will change. What you think is really deep and insightful today will seem shallow and immature in a few years. And you don't want something you will later think is childish permanently etched on your body.)

19. Pay attention to the short run…

People who care about you are always talking about your future: what courses to take for your career, what sports will help you get into college, what to look for in the person you're going to marry. All that stuff is important to think about. But don't let planning for your future consume your present. Do some things just because they're fun now. Take that art appreciation class just because it would be fun to learn about it. Play Injustice just to see Wonder Woman kick Batman's ass. Read those Deadpool comic books just because they're wickedly funny.

Tony Tomsic Getty Images

20. …But keep your eye on the long run.

Most of what's important to you now won't be in a few years. Friends will change. Priorities will shift. That can be a pretty scary prospect. Most boys are afraid of growing into their nightmare version of an adult: the flaccid, self-righteous, humorless sack of meat dumped on the couch shouting commands or barking advice that begins, "When I was your age…." Don't worry, it doesn't have to turn out that way. Another favorite quote of mine is from Thomas Jefferson: "Eternal vigilance is the price of liberty." He meant that the cost of freedom is to always be watching for someone wanting to take that freedom away, but a variation of that quote can apply here: "The price of being a man is eternal vigilance." Know who you are, what you stand for, watch for any assaults on your principles, but always be open to change if the evidence warrants it.

MORE KAREEM: 20 Things I Wish I Knew Before I Turned 30

PLUS: KAJ's Full Archive on Esquire.com

This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.io