It is most certainly *not* psychological. It's just age, mostly. You'll find out in 10-20 years.
I’m not old but I have had several knee injuries from sports and my knee hurts when it rains. My doctor said it has something to do with barometric pressure. But if I tried to explain passed that I would just be talking nonsense because I don’t actually know.
Sorry i guess i wasn't clear. The link is to the page were the translator points out what actually causes it, so essentially i learned something new
Follow the link, the translator elaborates on it (⌒▽⌒)
I've always wondered why people say they joint and/or an old injury hurts when it rains, i always assumed it was psychological. https://www.mangago.zone/read-manga/new_alpha_son_old_omega_father/uu/to_chapter-1/pg-7/
Oh LOOOOL and the note about not translating the divorce form, made me chuckle