Another aspect could be Naruto's training with Jiraiya. Boruto might read in the fanfiction about how Naruto traveled with Jiraiya, trained hard, and grew not just in strength but also in character. Jiraiya taught Naruto many important lessons about life and being a shinobi. This could give Boruto a newfound respect for his father's journey to becoming the Hokage.
One of the most shocking revelations could be Naruto's early days as an outcast. Boruto, who has always known his father as a respected figure, would be surprised to learn that Naruto was once shunned by the village. Another could be the danger Naruto faced as a young ninja, like fighting against the Akatsuki. It's so different from Boruto's relatively more sheltered life in the beginning.
Well, Boruto could be very inspired. Naruto's past is full of struggles, from not having parents around to being constantly underestimated. When Boruto discovers this in the fanfiction, he might realize that his own problems are not as big as he thought. He could be motivated to work harder and not take for granted the things he has, seeing how much Naruto had to fight for everything.
One key event could be Naruto's time at the Ninja Academy. He was often alone and had no one to practice with, yet he still persevered. Boruto would see how Naruto's determination started early. Another event might be when Naruto fought against Haku and Zabuza. It was a dangerous battle that showed Naruto's courage. And of course, Naruto's training with Jiraiya would be important. Jiraiya taught Naruto so much, and Boruto would understand how this mentorship shaped Naruto into the person he became.
It could strengthen their bond. As Boruto learns about Naruto's past achievements and the challenges he overcame, he might feel proud to be his son. He may start to see Naruto not just as his father but also as a hero, which would bring them closer together. Boruto might be inspired to follow in Naruto's footsteps more wholeheartedly.
In this kind of fanfiction, one revelation could be that Dumbledore hid the true nature of certain magical artifacts from Harry. For example, he might have concealed the real powers or the dark secrets associated with an object like the Marauder's Map.
One interesting plotline could be exploring Naruto's early days of training with Jiraiya in more detail. Maybe showing his struggles and how he overcame them during that time.
Perhaps Harry discovers that Snape had a much deeper connection to his mother than he initially thought. Snape's love for Lily Potter could be explored in more detail, showing that his actions towards Harry were influenced by his feelings for Lily. This could involve Snape secretly protecting Harry in ways that were not obvious in the original story.
Boruto might be in awe. He has always known his father as the Hokage, a powerful and respected figure. Seeing Naruto's past full of struggles, loneliness, and determination would make him realize how far his father has come. It could also make Boruto more empathetic towards Naruto and perhaps inspire him to be more like his father in some ways.
Definitely Naruto and Sasuke. In a 'past Naruto meets Boruto' fanfiction, if Sasuke was also involved in the meeting, it would be really cool. Boruto could see the dynamic between his father and Sasuke, two of the most powerful ninjas. He could learn about their past rivalries and how they overcame them to become allies. It would be a great opportunity for Boruto to understand the importance of having a strong bond with your comrades.
Probably the fact that he was a Horcrux. This was a huge part of his past and his connection to Voldemort. It's a very dark and mysterious aspect that his kids would find both fascinating and terrifying.