It can be all "far fetched and highly unlikeLy" you want, but I was thinking exactly the same xD
I LITERALLY SAID OH MYGOD AFTER YOU BROUGHT THE TWIN THEORY CAUSE I DIDN'T THINK OF THAT but its just probably a little unlikely though cause I forgot that it seems that Dohyun remembers a few things like a young Sungho (I believe he's regaining a few memories) BUT I COULD BE WRONG AND IF IT TURNS OUT HE HAS A TWIN THAT'S AN OFFICIAL MIND BLOWN .
LOL, me too! Any time, now, I'm going to start thinking Sungho kidnapped his alien clone or something .... Imagine if Sungho realized he's not the real Dohyun, but an alien sent to take his place in order to invade humanity? (≧∀≦)
Wow... You've got quite an imagination there xD
Okay so I've been thinking right about why dohyun doesn't remember and either he has amnesia or wait for.... he has a twin. I know it's really far fetched and highly unlikely but there's gotta be a reason he doesn't remember. Cause I doubt you could forget all that experience.