To become great, find a mentor and become a carbon copy of him/her. Forget individuality! (Team 7 and the Sannin, Lee and Gai, Konahamaru and Naruto, Shikamaru and Asuma).
Remember kids, if a bad guy asks you to abandon your friends and join his side, always go for it. It's a super-quick and easy route to becoming an unstoppable one-man army with lots of hax powers! And no need to worry about the bad guy's motives, as you can just kill him once he's given you enough power.
Girls can't fight. They can only heal and cry over the guys who can fight. If a girl can fight, something is very wrong with her.
But it doesn't matter in the end, as all they really want is to have boyfriends and get married. Yes, even if they're leaders of ninja villages or if the object of their desire tried to kill them, they still wish to be subservient to men.
Recruiting immature prepubescent children into your military is perfectly acceptable because you love them.
Remember, if your friend turns evil, he is still your friend and you should do everything you can to save him and make excuses for him, even if he wants to kill all of your friends.
Also try to stop your new boss (albeit a Lawful Evil one) from killing him even if he's totally justified by both international laws and the laws of your villages.
People only matter if YOU know them. The life of a murderer who happens to be your friend is far more important than the lives of any victims that were strangers to you. After all, your friend has all kinds of issues about lost loved ones and it's not like their victims could have any of those, no family or friends who'll EACH now be going through grief every bit as agonising as your buddy!
A promise is a promise, and you must fulfill it. Even if it causes you suffering, possible death, to lose three years of your life that you could be doing something more important with, to make things worse for everyone...
That's probably the INTENDED Aesop.
So the lesson here is never make promises?
Also, your true love is the guy/girl that ignores you. Always.
Screw therapy, the way to get out of any depression/angst period is to decide you want to become stronger, for some vague reason.
All problems can be solved by letting a homicidal fox demon control your body for a bit.
This could also be said (to a much lesser extent, and with the exception of anyone who kills the main character) of YuYu Hakusho
People who are different will never understand each other. In order for the understanding to happen, both must live the exact same life.
Also, it's okay to kill your whole family to save your village from a coup. Even if said village was pushing your family with false accusations based on long past events. Even if only some members of your family were involved in the coup. It's okay to kill your elderly and youngling relatives, even your parents, and then turn your brother into a raving lunatic for some stupid Gambit Roulette and still hope for him to have a normal life. Don't worry, you will be absolutely praised for your actions.
The best method for this is to show him the destruction over and over again for mental equivalent of 72 hours twice
And it's also okay for other people to be informed of such and keep quiet, even if relating it to your leader might open the possibility of diplomacy with said brother who's been turned pure evil. And it's wrong that said brother is PISSED OFF because his whole clan was killed for this stupid Gambit Roulette! He should just suck it up, right?
These are also all great qualities for a potential Hokage to have.
No, it's okay to kill everyone associated with the village, despite having no knowledge of the truth of the incident whatsoever.
Also, in the improbable case of your brother going insane from all the shit you put him and your family through and deciding to ignore your mindset and go on to avenge the clan, it's okay to essentially brainwash him into being a slave to the village for life, essentially killing his free-will and condemning him to serve his family's murderers. Itachi, you should be the Poster Boy of this page, you know that?
It's only the thought that counts. As well as destroying your brother sanity, torturing your fellow village protectors is OK too. Because you're the bestest shinobi EVER!!
It's okay to hate a child because he has a demon inside them. It's also perfectly logical to ostracize him, make him feel unloved. He will, every time, use his powers to protect you. He will never once think to use his powers to unleash unholy hell on you and your loved ones as payback for all the crap you've put him through.
Bonus points when the guy who sacrificed his life to stop said demon (aka their renowned leader) asks you to make him a hero.
It's better to be dead than to raise your son without your smoking hot wife.
To get stronger one needs friends, preferably just their eyes.
Revenge is bad. UNLESS the guy you're taking revenge on is a different religion than you, in which case, fuck him.
The true Aesop is: revenge is only bad if your target is an Uchiha or possesses Uchiha eyes. Everyone else is okay to unleash your vengeance upon them.
If you attempt to change to world for the better, there is a good chance that the slightest mistake will cause you to fail horribly, cause the deaths of nearly everyone you care about, and eventually make you pure evil.
If you are not descended from the mythical savior of the world, you are utterly irrelevant.
If someone tries to kill you, he is your best friend, and you should devote the rest of your life to preventing other people from holding him accountable for his crimes.
If someone destroys your village and kills most of the people in it, you should totally spare him. It will bring everyone he killed back to life and make everyone love you.
If a girl confesses her love for you and is almost killed right in front of you, you should ignore her completely.
It's okay to risk the destruction of your village/the end of the world by letting the person the enemy wants to capture fight them as long as you have faith in him.
You also have to be evil too. Since being good doesn't amount to anything.
Because you'll be Easily Forgiven later. Despite ruining many lives. Hell, you're the coolest despite the fact that everything about your actions says otherwise.
It's fine if a guy stabs you and leaves you for dead if he's cute or is your so-called best friend.
Abandoning your friends to complete the mission is the right thing to do. If you help them, everything will go to shit.
When you decide that you need to die for the greater good. Force your friend to do it. Never mind about their feelings. It's for the greater good, right!
If you have a choice between a) a girl who hits you if you so much as insinuate that you're together and b) a girl who's always nice to you, has risked her life for your sake, and has told you that she loves you, always pick the former.
Tecnically, this aesop applies to Tsunderes in general.
It doesn't matter who you are or who your parents were, all you need to become strong is to try as hard as you can. You make your own destiny, and nobody can- oh wait, no, never mind. To become powerful all you need is a demon sealed inside you and to be descended from The Chosen One.
How to get people to work together:
: Be absurdly late.
: Give out false information.
: Giving out hints (even if they're vague) is a no-no.
: Threaten them.
You also have every right to get angry if they do follow your instructions.
Also the hidden lesson is don't trust your superiors and trust your teammates because the former will betray you and the latter will not.
That all people are incredibly stupid. ALWAYS.
Students cannot surpass their masters. No matter how many people voice that you've done so, when put into practice, the previous generation is always the bigger fish (even back when they were your age).
Neglecting your child is okay when you have an entire village to run with no assistants to take your place. (Apart from your ability to create up to thousands of magical clones of yourself that is.) It is especially okay when they are feeling the same neglect you did as a child.
Marry your first love. Even if he's tried to kill you, he was just misunderstood. Moving on would apparently make you a horrible person.