
i don't think he remembers him in the third life. it was shown how hyung fell in love and tried to make hosik love him back but there was no mention of past memories on hyung's part.
let alone, it was hosik that had that dream of their first life together, not hyung.
imo the hyung in the second life was effected by the severe grief the first hyung had by witnessing hosik die and that's why he still had his past memories.
the intense trauma to his psyche made him unable to forget. and that also explains why second hosik doesn't remember. death is always more painful for those that stay behind after all.
Spoiler, I think
Does Hyung always remember Hosik? As in like, every generation, there is always a Hosik and always a Hyung and Hyung always remembers Hosik but Hosik never remembers him so he just has to live life each time looking for and having Hosik fall in love with him all over again? Because the extras already make my heart hurt and if that's the life hyung has to live with, it makes me hurt more