After watching dramas for quite a long time, I can say that to me there's a lot of good shows but few that I can confidently say perfect. And that's why, this is the first drama that I'm re-watching.
You will be addicted from the first episode and it manages to keep the quality the whole run. Looking at the tags, seeing trauma and mental illness you might think it's going to be overly dramatic and at time hard to watch, but you will be surprised, since the plot is actually very funny and wholesome. There are so many questions and motive that you will start guessing from the episode one, be it from main character or side characters. Even small characters have such strong personalities that you can't just ignore them, from the quirky doctor at the hospital to lovable couple of patients. The lead couple hold a interesting relationship, the ML despite being a "good" person, is broken and lives a very limited life, because of that he starts to be moved by the FL, who is after him from the first moment they met.

ANOTHER STRONG POINT. THE. OST. IS AMAZING!! I have it saved and whenever it comes up, I get the feeling I need to re-watch the whole show...

(somewhat SPOILER)
This is not to degrade the show but some of the situation cause by the characters with mental illness were a bit hard to watch again, not sure if its a good or bad thing (example: I was hoping his brother would act differently sometimes because I knew he was causing a problem that would be solved soon, so it felt like a bit of a waste of time( BUT THATS ON ME 100%))
deer jokes never got old!