Responses

I'm pretty sure it was this: http://www.mangago.zone/read-manga/warehouse/uu/warehouse-chapter-1/34/
he nearly died and lost parts of his memory i think

But according to the Q&A Dohyun just lives in the present and doesn't care about the past that's why he easily forget things
Does dohyun have some kind of mental illness? Why does he forget everything