In order to create a show that will leave a lasting impression, you need pretty much A+ on every department, and IOTL passes with flying colors! - The story deals with topics regarding mental illness and manages to really dwelve into them; the writers did a great job of taking the matter seriously and presenting it in a profound way, you really feel the sincere approach on that front. - The acting is absolutely superb from every single cast member; they all did a fantastic job and balanced out well both the comical and more serious aspects of the series. (+add to that, that Jo In Sung and Gong Hyo Jin have great chemistry; their scenes together was such a joy to watch.) - The music was fantastically picked; there's not a single song that won't be stuck in your head after you finish watching it. All in all, an absolute gem of a series that will take you for a ride and never let you down. A solid drama from start to finish that will truly stay in your heart and maybe teach you a couple things. I know it taught me! I give it a 10 in every category - and I rarely give 10s, but it really doesn't deserve any less. A huge kudos to everyone that worked to create this, they all did an excellent job. Phenomenal series, simply put.