Naruto Uzumaki was facing a dilemma.
Whenever he wasn't busy acting as the Toad Sage since Jiraiya's death all those years ago, he would train. One could argue that, with the use of Shadow Clones, he could get a year's training in a day, but Naruto was one to learn a new jutsu head-on, before delegating his Shadow Clone army to smooth out the flaws of any new jutsu he might have been learning.
Shadow Clones wouldn't help Naruto with fitness either, something that was necessary to maintain, even with his staggering amount of stamina.
If he learned many jutsu, he might have bragged about his extensive moveset, but unlike his former sensei Kakashi Hatake, he didn't need to know one thousand jutsu.
That is what Naruto would think about whenever his unofficial student Konohamaru came to visit him on one of his off-days from Chūnin duty (which was far more time-consuming than being the Toad Sage, Naruto realized). Konohamaru was a lot like him and would absorb any lesson Naruto taught him like a sponge.
"Hey, Boss!"
"What is it now, Konohamaru? Come here to learn another jutsu?" Naruto asked.
Konohamaru beamed. "Yeah! You know me so well, Naruto."
"Not really, you always come to me whenever you want to learn a new jutsu. Well, you know the drill." Every time Konohamaru would visit Naruto, he would have to show him the jutsu he learned at their last training session.
"Alright, here goes!" Konohamaru began forming a sphere of blue energy in his hand. The single-handed Rasengan came easily to both Naruto and Konohamaru after significant (Shadow Clone-enhanced) training.
"Well, Konohamaru, it looks like you can form a one-handed Rasengan. Can you take it further?"
"Sure, sure! Just give me a second to focus." Konohamaru took out his other hand and began adding his chakra nature to the Rasengan. The blue ball of spiralling energy began taking on a orange-red hue, becoming more like an inferno as Konohamaru added more of his fire-based chakra nature.
"Yeah, I've almost got it!" Konohamaru stopped adding his chakra nature, thinking that he added enough chakra to the Rasengan. He didn't.
The premature Fire Style: Rasengan burned out, leaving a trail of burns along Konohamaru's hand.
"Gah! I almost had it," Konohamaru blurted out, more worried about failing the jutsu than his injured hand. Burned fingers and skin were more of a minor irritation to the teenager than a major setback.
"Don't worry about failing the jutsu, Konohamaru," Naruto said in an attempt to console his pseudo-student. While Konohamaru was busy forming the Rasengan, Naruto took out one of his special kunai, spinning it on his index finger. "It took me a while to complete the Rasengan and even after I did, I had to practice a lot so that I could perfect it."
"Yeah, but I almost had it! Just you wait, Naruto, the next time we meet, I'll have completed the Rasengan and then you have to teach me a new jutsu!" Konohamaru exclaimed.
Is this how Kakashi-sensei felt whenever I would ask him to teach me a new jutsu? Huh. Well, I can't really say anything about how Konohamaru's like, since I was the same way. Naruto gave Konohamaru a soft smile, "Why do want to learn so many new jutsu from me?"
"You're the strongest shinobi in the village and you're my rival!" Konohamaru explained. Naruto felt proud when he heard his young rival's words. "If I learn all your jutsu, I'll be one step closer to surpassing you and becoming Hokage!" After you become Hokage, of course, Konohamaru thought, but didn't say out loud.
"You know, Konohamaru, after you complete the Rasengan, you'll have learned all the jutsu I can possibily teach you. I mean, I can't teach you any of my Wind Style techniques. You can't be taught Toad Sage Mode since you've signed your grandfather's Monkey Summoning Contract or Nine-Tailed Chakra Mode for, well, obvious reasons."
Naruto's exploits during the Fourth Shinobi World War became common knowledge after said war's completion. Konohamaru, of course, was awed at how strong Naruto became. Not that it stopped him from trying to surpass his rival and teacher.
"So why don't you learn jutsu of other chakra natures, like Fire Style?" Konohamaru asked.
"I don't need to."
"Wha...?" Konohamaru asked, confused at Naruto's words.
"I used to be all gung-ho about learning new jutsu." Naruto chuckled at all the memories of him begging Kakashi-sensei or the 'Pervy Sage' for new jutsu. "But then I realized, I don't need to learn many new jutsu – I have all the jutsu I could need."
Naruto continued. "You of all people should know how useful Shadow Clones are. It is the world's greatest jutsu when used by a person awesome enough to handle its power. Rasengan is a great attack move and the Sexy Jutsu, while controversial, is a great espionage tool.
"Even with Shadow Clones, you can either know a thousand jutsu and suck at using them, or be awesome at using only a few jutsu, like me." Maybe that's why Kakashi-sensei only uses a few jutsu, even if he did copy over a thousand, Naruto mused. "It won't work for everyone, so I'd recommend learning some more jutsu, though."
The sun was setting over the Hokage monument, signifying the end of the day and the conversation. "Well, Konohamaru. It's been great talking to you." Naruto threw up his kunai in the air, but when it came down, he failed to catch it, the kunai slipped out of his grasp and fell on the grass. Damn, still need to get used to the feel of the kunai. "It's time for me to eat my post-training bowl of ramen. I'll see you around." With that being said, Naruto disappeared in a flash of yellow light.
Konohamaru was so shocked to see Naruto teleport that he initially didn't notice that the kunai that Naruto dropped was still laying on the floor. After overcoming his shock, he picked up the kunai.
"Hmm, this is an interesting kunai. I can't help but feel I've seen it somewhere." The kunai, to Konohamaru, felt heavier. He examined it, noticing its peculiar design. What kind of kunai has three prongs? And what's with the yellow sealing tag? Then it hit him.
"No way!" Konohamaru pocketed the kunai and ran home, hoping to get an early night's sleep so that he could train all day tomorrow. While he was doing that, something important that Naruto said to him before was being repeated in his thoughts.
A true ninja never reveals all of his jutsu.
Author's Note: The above is a reflection of what I think Naruto might think about learning new techniques. It's not my personal opinion, it's an analysis. Naruto's method of attack relies on his extraordinary stamina and firepower to execute properly. While it would work for Konohamaru to an extent, he would need to learn more techniques in order to compensate for his inferior stamina. It won't work for someone like Kakashi, who has inferior stamina to Naruto, so he needs as many techniques as possible that can get the job done effectively and quickly.