The Ending: WTH?

I absolutely love actor, Nam Joo-hyuk. He was awesome in the Bride of Habaek. After watching that series on Netflix I began looking up his other roles.

It's not surprising that his acting was also superb in Twenty Five Twenty One and he really played the role well. What gets me though is the ending of Twenty Five Twenty One.

Oh my god...the unanswered questions. Too many of them to list. It's not great when you see different sites on the internet trying to explain the ending of a movie or tv series because the ending is so vague that too many people have far too many questions etc...