Naruto doesn't respond for a few moments, absorbing the nature and the truth of the voice's accurate claims. He did meet Teuchi-jiji and his daughter when he was eight. The civilian adults stopped attacking him long before that but teenage bullies were another matter entirely and would chase him down every time they spotted him. It's true no one would know what Teuchi-jiji and Ayame-nee did...
"Wait," Naruto sluggishly speculates aloud. "They would know. Jiji and Nee-chan could've told you."
'I mean I doubt they ever would, but fine,' the voice states. 'We're low on time so I'll name a few things quickly; stuff only we know. We- ...you first developed the Oiroke no Jutsu(Sexy Technique) because you noticed how girls are treated better and how much more attention they'd get. You found a box of Barely Legal and Raw Kunoichi magazines in the dump, peeped on girls in the bath houses, and finished the jutsu in six months.' Though wide-eyed in shock and red in the face, Naruto refutes nothing as the voice continues, 'you found your green goggles in the park by the academy. You stayed there for nearly three hours waiting to see if anyone would come back for them. When no one did, you kept it on your head in hopes someone might recognize them. You found a fat toad in that pond by the Hyūga compound. You became best friends and named him Gama-chan.' Naruto can hear the levity in his voice all but disappear when he continues, 'we were really sad when some of the Hyūga kids killed him. That was a hard month, but while you were scavenging the dump, you found a toad wallet that reminded you of Gama-chan and kept it. Your shinobi tools were mostly scavenged from corpses in Training Ground 44. Everything else in your apartment is a hand-me-down, clearance sale, or found in the dump because nearly all the shops in the village make you pay more. You sent a letter to yourself when you first learned how to write because you never got any mail and you wanted to know what it felt like-'
"Okay," Naruto finally said, calling an end to the voice's rather depressing tirade of his life. "Uh... whatever, I still don't think you're me from the future, but, I'll hear you out. Start by telling me how awesome I become. How fast do I become Hokage?"
'First,' the voice interrupts, cutting off some of Naruto's excitement. 'You have to know I won't always be with you like this—speaking to you like this isn't a constant thing. What I'm doing takes a lot of effort and concentration to keep up. I'll explain what that is next time. As we speak, it's getting harder and harder to stay, so until I can get a better handle on this, for now, I can only talk for minutes at a time, maybe twenty if I really try.'
"Sounds complicated," Naruto grumbles. "Why can't you tell me now?"
'Not enough time,' the voice says. 'I'll be back, though—once I've rested—but for these last few minutes, I just want to explain a bit of why I'm here. The short version is, there's a fourth great shinobi war, and basically, we lose. Lots of people we know will die, and the rest are trapped in a never-ending, unbreakable genjutsu. I'll explain more next time but, the reason we lost is because I wasn't strong enough. Team seven, our friends, our village, the entire shinobi world is a slave to this really bad guy because we weren't strong enough to stop him. It was all too easy to manipulate us—the nations, I mean—because we were all too busy hating each other and fighting amongst ourselves to stop and think. In the end, we couldn't stop this cycle of hate, which meant, we couldn't stop him.'
"Are you serious?" Naruto huffs with wide eyes.
'Hehe, yeah, I guess that would be hard for anyone to accept,' the voice admits. 'But it's true. There's something else, and this is going to be really important. You already know Kage Bunshin, right?'
"...Yeah," Naruto slowly acknowledges.
'Good,' the voice affirms. 'What you probably don't know—or won't know until years later for some odd reason—is that any knowledge or experience your bunshin experiences, you'll learn as well after it's dispelled. T-Try this... if you don't... believe me.'
"Oi, oi, Naru-nii, you okay?" Naruto asks uneasily, sensing the struggle in the Voice's speech.
'I only have... seconds,' Naru-nii barely manages to get out. 'Make... a Kage-Bunshin. Make... it... talk... to Teuchi-jiji... or Iruka-sensei... somebody. Then... dispel it. You'll... learn... e.. e.. every... thing... it... learnned.'
Quiet fills Naruto's expectation of further conversation. After several moments of silence, Naruto can't help but call out, "Neh, Naru-nii? Naru-nii, you still there?" Other than the wind breezing through grass, leaves, and branches, and the birds singing, Naruto is met with silence.
Head tilting to the side, Naruto scratches his smooth hairless chin, pondering everything that's happened. He questions the merits of this complicated prank... if he can even call it a prank. Humming inquisitively against the rustling sounds of blowing trees, he slowly reflects on the voice and how it knew things about him that no one else could know. Naruto was fairly sure if the voice continued, it would've only mentioned more anecdotes about his outcast of a life, so, it's either the most elaborate prank in the history of pranks, or...
"Meh!" Naruto shrugs forming the hand seals for the Kage Bunshin. He's always been a practical guy, not that he wouldn't love the brains to think his way through problems but the academy pointed out to him a long time ago he just wasn't smart enough for that kind of rational approach. What's more, he isn't really doing anything dangerous, or suspect, like how Mizuki tricked him into stealing the Scroll of Seals.
"Kage Bunshin no Jutsu!" From a quickly evaporating puff of white smoke, nine shadow clones of himself pop into existence. "He said one... but whatever," Naruto mumbles, taking a commanding step in front of his troops. "Alright, listen up. I want three of you to go... somewhere. Ah! One goes to Ayame-nee, one to Ji-chan, and one to... Iruka-sensei. Break into his room if you have. Just see him. You can dispel after that."
With little more than a quick look between the nine, three immediately break off. How those three knew they were the ones, the original didn't know, nor care. "What about us," one clone calls.
"The rest of you go to look for the shuriken I threw earlier. When you find one, leave it there and dispel. I guess I'll learn where it is."
"Yosh!" The rest of the clones call, fists in the air, and Naruto watches them rush off to get to work, all the while shrinking a bit at what he's heard. It's not every day you're told the fate of the entire shinobi world rests on your shoulders, much less failed when it mattered. Lives of families, friends, strangers, ninja, civilian, and everything in between somehow are depending on him and he doesn't know why. Ji-chan is the strongest person he knows. Why wouldn't they rely on him instead?
If for some absolutely insane reason, everything Naru-nii said turns out to be true, he can't help but compare it to Iruka-sensei. He failed to keep his sensei safe, even ended up hurting him worse in his great panic, and that was only one person. What Naru-nii is talking about is for the fate of everyone; Ji-chan, Teuchi-jiji, Ayame-nee, Iruka-sensei, Sakura-chan, maybe even the people that hate him. Naruto can't see how everyone could depend on him like that. Wouldn't he just fail to keep everyone safe as he had his favorite sensei? Naruto felt restless, like he's been sitting for too long and itching to get up. All these questions he has no answers for is making him doubt himself.
"This has to be a prank!" Naruto calls out. 'How could it not be?' He thinks, when suddenly information, a memory, knowledge he didn't have of a lost shiruken he tossed somewhere in the woods, pops into his mind. It feels like a little strained pulling, like someone quickly ripping a single strand of hair from his head. As he takes in the entire memory, he questions how true it is, how real this is. His first step to fetch his newly recalled shuriken is interrupted with another flash-memory, leaping into his mind, cause the ache on his brain to momentarily sharpen. Before too long, Naruto learns where all six of his shuriken went and has a headache similar to prolonged brain freeze for his efforts. The concentrated, lethargic pricks of pain don't last long—a couple minutes or so—and it's not nearly the worst pain he's ever experienced. However, it's an effect he makes a note of nonetheless.
With all his worn throwing stars in his pouch, the first of his shadow's conversations floods his mind. Naruto squints his eyes at the pinch to his brain as a whole conversation with Ayame-nee plays out in his mind. It was a simple conversation. Nothing of note or relevance other than the usual, 'hey, Ayame-nee,' and, 'how's it going?' Though she had finished their short conversation with a phrase she's often directed at him. "Nothing but the freshest ingredients for our favorite customer."
No sooner had he thought that sounds just like her, did another memory materialize in his mind. He was in the Hokage tower. He tried to see Ji-chan but his secretary had informed him that the Hogake was in a council meeting.
"That should be easy to double check," Naruto says to himself. Whether the voice knew about the meeting or not didn't matter. He himself didn't know about the meeting, so if there is, in fact, a meeting, the Voice will have told him something about this jutsu that neither Kakashi-sensei or Ji-chan informed him of. He's not angry with them, but he certainly doesn't understand why they wouldn't mention this neat little trick. If he wasn't a serious shinobi of the Leaf, he would certainly be planning the biggest chronicle of pranks for the year.
The final memory he received on the path home. It was a hurried memory. His clone had been found trying to get past the entrance, and they chased after him. The majority of the staff may be talented in saving lives but he's been chased for most of his. He managed to hold them off until he finally found Iruka-sensei. He was asleep, propped up on his bed with at least five pillows and a harness around his torso, keeping him up. It was the last image before his clone ended its existence, but it was enough consolation just to see Iruka-sensei.
'He didn't look great,' mentally Naruto admits and if he were honest with himself, he's having a hard time keeping the guilt from assuming control. So much so, in fact, he stops his journey back home in favor of returning to Training Ground 28 to continue training. He may or may not have spoken to his future self... he may or may not have been duped... but he wasn't going to waste any time on his path to get stronger. If everything Naru-nii said turns out to actually be true, he will not fail again, just like he won't fail Iruka-sensei again.