I've watched this entire series through to the end because I'm learning Korean, and it was definitely helpful in at least teaching me the phrases of "I like(d) you" and "I love(d) you" which are repeated throughout the show ad nauseum.
The show isn't all bad. I enjoyed the photography and the calligraphy depicted in the show. The side story of the young woman born poor with the boyfriend who would do anything for her is empathetic at least. There were some genuine touching moments in that regard. There were some nice comedic moments as well, but they were too seldom.
So, what isn't there to like about this series? It romanticizes toxic relationships/infatuations to the point where the viewer has to question why anyone would put themselves through 10 years of self-loathing wondering why the other person doesn't like them back.
I honestly could not root for the main couple let alone a love triangle that forces the male lead to confess his feelings due to jealousy. Even to the end, you can see how toxic the main relationship is, and it is disheartening.
I know there is still some taboo in Korea to discuss psychological and/or emotional problems. Perhaps, if they focused more on their personal growth apart, I would have found the series more engaging. For those who want to just cheer on an ill-fated Kdrama relationship, you can take a stab at this show. Thanks for reading.