It started out with something as simple as trying to count all the stars in the sky.
Mito laughed lightly when Gon had asked how many stars there were on such a clear night, and told him that there were too many to count. The fact that there were more stars that what he could see right now appalled young Gon, and that was the start of his fascination with the sky. What books he could find on the topic and get his little hands on were read through, the pages' corners folded as temporary books marks. He asked fishermen about the sky, about everything that could dwell within it and everything beyond. Although some laughed, some told him amazing stories about space and all the universes out there. Those only fueled Gon's curiosity about the sky, his universe, the universes out there, and how much space contained. Oh, and of course, he still wondered how many stars were in the sky.
So the next time Killua met Gon, he found a more mature teenager pouring over thick books with a tired yet somehow excited expression. And when he tried talking to him, all that came out of Gon's mouth was something about exoplanets, universes, black holes, and wormholes. When Gon began to speak about the question whether there was other life out there or if everyone was actually from Mars, Killua scoffed and told him that it was all nonsense.
"Killua, you're underestimating the universe!" Wildly gesturing with his hands, Gon restarted to blather about how great space was and how many solar systems were out there. Uninterested (but glad he got to see his friend again), Killua made up some excuse to get out of the one-sided conversation, and Gon apologized for probably boring him before going into a coughing fit. Saying it was fine, Killua left.
He shouldn't have simply ignored that coughing fit.
So the next time Killua met Gon, he found a horribly sick teenager (nearly adult) reading a book about (guess what) space. This time, he stayed by his side and listened to all the facts Gon was able to say about the sky and universe, despite being more worried about Gon's condition rather than if aliens were out there and if they thought we were the aliens. What was boring before became a casual topic (through the sneezes, coughs, and headaches) and Killua grew rather interested. Gon knew how to tell a story (or report) and Killua got sucked into the black hole of space. Due to Gon being hospitalized, Killua went out and got the books for his sick friend. Sometimes, he would read them at the store before remembering Gon was waiting for him and rush to buy them and leave.
He really shouldn't have got caught up in that book.
"Haha, I never did get to find out how many stars there were in the sky."
Gon was right. Despite all this new information about all the interesting things that could be happening outside their planet, Killua underestimated the universe. He doubted its ability to give and take. He forgot about protecting what was right in front of him and instead focused on the untouchable. And suddenly, the world felt so cold, as if he was on the moon without a spacesuit. His Sun was destroyed right in front of his eyes and his world lost something to revolve around.
He underestimated the Sun's weakness and how the world would lose any meaning without it.
A/N: Hahha, sorry for not updating my other fic, I just had this stuck in my head for like a minute and I had to write about it.