Kuroko learned a few things when he first moved in with Aomine.
The first was that Aomine owned literally only one pair of jeans and sweatpants. This is because Aomine lived in basketball shorts. When he got home the first thing he would do, before even saying hello to Kuroko, was go change into a pair of shorts. Then he would come and talk to Kuroko about his day.
Aomine was also surprisingly organized. Everything in his kitchen was labeled, despite the fact that Aomine could make a total of five things. Macaroni and cheese, rice, pasta, cereal, and toast. They kept a book of takeout menus labeled 'cook book'. Akashi had let them know of his disapproval the first time he visited.
His collection of basketball shorts was organized by color and how often he wore them.
He had the fridge organized with one shelf for each type of food group, and arranged from there by expiration date. This took quite a bit of time after grocery shopping considering how much they had to buy to feed Aomine.
Kuroko had known that Aomine was not a morning person. He was completely useless before at least two cups of coffee. Kuroko still couldn't figure out how Aomine got to be so tall when coffee was supposed to stunt growth.
However, until they lived together, Kuroko wasn't aware of just how hard it was to make Aomine wake up in the morning or how much of a struggle it was for Kuroko to just get up on his own since Aomine would usually be pressed against Kuroko with his arms trapping Kuroko against him by the time Kuroko woke up.
After he learned how to worm his way out Aomine's arms he started trying different ways of getting him up. Alarms didn't work, pouring cold water on him just made him cocoon himself further into the blankets with mumbled complaints. Shaking him just resulted in the process of having to struggle his way out of Aomine's arms to repeat, because the other would just pull Kuroko to him to make the shaking stop. Kuroko wondered how Aomine had ever managed to wake himself up. For a little while a recording of Akashi threatening him to wake up worked, but after a few days Aomine's sleep idled brain was able to piece together that it was a recording and that Akashi wasn't actually there to kill him if he didn't get out of bed. Kuroko wasn't even surprised when it appeared that sex was the motivation that got Aomine to wake up. Apparently a blow job in the morning worked better than cold water.
Although, whenever Kuroko woke up in the middle of the night from a night mare, Aomine was right there, awake, at his side mumbling things like, "It's okay, Tetsu. Everything's fine. It was just a dream. I'm right here." as he placed light kisses all over Kuroko, running fingers through his messy hair to try and calm him down. Aomine would then refuse to go back to sleep until Kuroko was asleep again.
He also learned that Aomine had an unhealthy obsession with reality TV, despite hating everyone on it. Kuroko had tried to watch a few episodes with him, but ended up falling asleep with his head resting on Aomine's lap half way through each time.
Aomine learned things about Kuroko as well.
For instance, Kuroko was a morning person. Every time Kuroko managed to wake him up in the morning Aomine would look at the clock on their nightstand and mourn the loss of his precious sleep. Kuroko's mouth on him made him forget about that for a little while, but it came back to him as he was making coffee before taking a shower with Kuroko. Which, by the way, Kuroko liked his showers way too hot.
He also learned that Kuroko had a surprisingly high alcohol tolerance.
He'd been drunk around Kuroko before they lived together, and seen Kuroko drink before, but it was always around a lot of people, so he really didn't how long it took for Kuroko to get tipsy.
Aomine didn't understand how someone so small, who hardly ate, could consume so much vodka without even flinching. He'd asked Midorima, since the other was a doctor, but Midorima's explanation and lecture on how drinking was bad –Aomine had seen the bastard so wasted that he'd dared to insult Akashi, he had no room to talk- got boring, so Aomine ended up spacing out.
But, when Kuroko was drunk around just Aomine . . . well, it was certainly an educational experience.
"Daiki, did you know that the distance from here to the sun is 150 million kilometers away?"
"I did not. Did you know that the distance from here to the sun is just about the last thing I want to hear about while you're touching my dick?" Aomine replied.
"I thought it was interesting." Kuroko said, pouting a bit at him, and stopping the movement of his hand.
"If I tell you it's interesting, will you please start moving your hand again?" Aomine asked, frustration clear in his voice.
Kuroko nodded.
"It's the most interesting thing from here to the sun!" Aomine exclaimed, a bit exasperated. The hand started moving again.
"That's 93 million miles if you want to tell Kagami-kun." Kuroko told him after they had both gotten off.
"Well, I'm certainly not telling him right now." Aomine replied after the moment it took to figure out what the hell Kuroko was talking about.
"Why not?"
"Are you being serious right now?"
"Yes."
"Because I don't know where my phone is, I have your come on my hand, and it's past midnight. Also, I don't make a habit of telling people random facts about the distance from the earth to the sun, especially not people who I only talk to for you. Also, he is Japanese. He knows the metric system. He's not actually American enough to need the distance in miles." Aomine listed the reasons.
"That's fair." Aomine relaxed, thinking the conversation was over. "Do you think he'd be more interested in the distance from here to Pluto? It's seven and a half billion kilometers."
Aomine groaned and covered his face with a pillow. "Tetsu, I really don't think he cares about astronomy. I don't know why you do either. You teach Kindergarteners." He mumbled into the pillow.
The next day he sent a text to Kise. What does it mean when your boyfriend keeps on talking about space while he's drunk?
He didn't get a reply.
Aomine also learned how much Kuroko cared about his kindergarten class. He'd found Kuroko passed out, slumped over a lesson plan several times, and each time he ended up carrying him to bed. Only for Kuroko to freak out in the morning because he fell asleep instead of finishing.
He learned that Kuroko's worst nightmares are about losing Aomine. He'd woken up a few times to the sound of Kuroko's gasp for air and attempt to bolt into a sitting position. After that he couldn't sleep until he was sure that Kuroko was okay and sleeping peacefully.
Most of all, they learned about what a pain it is for two men to share a bathroom when trying to get ready in the morning.
I'm sure there is something about how much they love each other in there, but seriously. They don't just share a shower for the shower sex. They need to share if they want to have time to get to work on time. Plus, Aomine would fall asleep in the shower if Kuroko weren't there. Also, the sink isn't big enough for both of them to shave or brush their teeth at the same time. They either need an extra bathroom or an extra sink.