I had this theory about they were childhood friends of some sorts and the brother or someone else who didn't want them to be friends locked him in a (dark) closet or something similar for a long time - what caused his insomnia, because he was scared sh!tless and cold and sleepy and (2nd theory) maybe the (not washed yet) Taekwondo uniform hung/ was stashed in a bag in there and he took the uniform to cover himself (cause cold and sleepy) and it gave him enough comfort to fall asleep. I first had a 🍇 theory but I like this one better 😭