Those who say that harmless schoolyard bullying is just that, harmless, need to take a step back and reevaluate the world. For what may seem like harmless teasing can have the potential to change the entire world. Just one insult, where there was a previous lack, can shake the foundations of an entire village.
A single insult, to a single blond-haired blue-eyed boy, can have ramifications no one ever dreamed of. It can have the power to flip the entire shinobi world upside down and completely rewrite history as we know it.
'You? Become Hokage? You're too dopey to become Hokage, imagine seeing your ugly mug up there on the Hokage Monument?!'
With just those three simple sentences, everything can change. With just those three simple sentences, wars can be waged and lives can be lost. With just those three simple sentences, a little boy can go from being the village pariah to the hero he was meant to be.
"I'll show them!" the blond-haired child grumbled to himself as he walked along the beaten paths of Konoha, trying to ignore the wide berth people were giving him, "I'll show them all I can become the most amazing Hokage ever, then they'll have to respect me, dattebayo!"
He looked up at the monument, imagining for just a second that it was his face up there, not a bunch of old dead dudes. And then he stopped, a wide grin appearing on his face as he thought up of his latest and greatest prank. All he needed was a few paintbrushes, some leftover paint from the last time he vandalized the monument, and a bucket or two of neon yellow paint.
"Hehehe," Naruto stopped to admire his handiwork, "Now they'll have to make me Hokage!" His logic, while somewhat flawed, was on the right track. Every Hokage had their face carved into the mountain, therefore if he had his face carved into the mountain, he would have to become Hokage, right?
Now Naruto was no expert carver, in fact, he didn't even know how he'd go about carving his face into the cliffside. Luckily there was a simpler solution, since he was going to become a Hokage that outdid all the others, why not just paint over their carvings to make them ones of him.
Twenty-four whiskers later (three on each side of all four Hokage's faces), four new yellow hairdos, and eight bright blue eyes later, he had managed to transform the entire Hokage Monument into statues of himself, sort of.
At the sound of approaching footsteps, the boy quickly took to the streets, it seemed the ANBU had finally caught on to his antics. How on earth did they not notice someone painting the largest monument in the whole village until he was nearly done with it, a process that could sometimes take hours? Sometimes, Naruto wondered if they let him do it, too amused at watching him defile a precious symbol of Konoha, to actually do their job and stop it from happening in the first place. That, or they just really enjoyed the subsequent chases around the village, complete with Naruto pelting them with rotten eggs and globs of paint and sparkle bombs.
They almost never caught him, a fact that really spoke to just how bad the standards of Konoha's ANBU had gotten that they couldn't find a single boy in a neon orange jumpsuit, who had absolutely no skill in stealth or tracking whatsoever. The only one who ever seemed to catch him was Iruka-sensei, an event which unfortunately didn't happen in this particular instance. Perhaps, if it did occur, things would have turned out differently, the monument would have gotten cleaned up before anyone had a chance to see the boy's 'improvements'.
Alas, in this story that did not happen. Naruto successfully outmaneuvered the ANBU and arrived safely at his apartment where he spent the next several hours bunkering down and giggling over the success of his prank before one of the ANBU finally had the idea to check where he lived.
Several hours during which the civilian and ninja population had plenty of time to see his latest masterpiece and realize just how much the young boy resembled the Yondaime. For with those whiskers, the carving of Minato could very well have been that of an older Naruto, in a way it was almost creepy how much the two resembled each other.
It was then that a few people remembered that the Fourth Hokage's late wife was one Kushina Uzumaki and everything completely fell apart. By the time Naruto had finally emerged from his hiding place, the news of his parentage had spread throughout almost all of Konoha.
At first, the civilian populace didn't know what to think, on one hand, he was the son of the village hero, while on the other hand, he was still the demon brat. But then they recalled how Minato wanted his son to be seen as a hero, they recalled all of the awful things they had done to the boy over the years, burdened by the knowledge he had been the son of the Yondaime.
Several villagers committed seppuku upon that realization, and several others resolved themselves to treat him with the same respect they showed the last Uchiha. There were still the few that resolved themselves, saying the fact he was the son of the Yondaime didn't change anything and continued to take out all their suffering on him, however, the majority of Konoha decided to start to treat the boy more like the human that he was, rather than the demon that he contained.
If this were all the effects that that single insult caused, it would have been well worth it overall. Alas, despite being a ninja village, Konoha was notoriously bad at keeping secrets, meaning every single hidden village and their mothers heard the news by the end of the week.
Iwa was especially upset at the news along with Kumo for obvious reasons and both soon formed an alliance before declaring war on Konoha. Kiri, despite being in the midst of its civil war also jumped in on the chance to attack the Kyuubi Jinchuriki. And of course, Suna wasn't going to step in to defend a jinchuriki since at the moment they were in the midst of all the assassination attempts on Gaara, their own jinchuriki.
Konoha, while fighting bravely, ultimately came to an unsightly end, leaving a power vacuum for the other villages to fill. This led to quite a bit of fighting between the various smaller villages and eventually the end of the shinobi world as we know it, seeing as how the villages were too busy squabbling amongst themselves to notice all of their jinchuriki going missing, much less band together to stop the Akatsuki. Thus Tobi's plan was moved forward by nearly a decade and successfully completed without anyone being the wiser.
A single insult can ruin everything. A single insult can have disastrous consequences. A single insult can destroy the world.