meiyorin

Alright, thank you so much!

thanks for pointing that out, indeed, I can't wait! :) do you perhaps know how long it usually takes for eng subs to appear?

to be fair I think you could be totally right! as Gang Doo himself has said in previous episode (I don't remember the number) he stopped taking these pills when he started to be around Moon Soo. Then when he found about Grandma and after her death he started taking them again.
There's something that makes me think that he is actually not experiencing any physical pain anymore, and just a trauma makes him think it's his knee, but really he's hurting in his head.