For Seo Joohyun, nothing was a more reassuring anchor than consistency. Some could even say consistency was her life, what with everything being a tight-knit routine with absolutely no room for compromise or exceptions.  She prided herself on being the most self-disciplined person she'd ever met and used that as incentive to keep herself in check.

To partially quote one Mr. Ferris Bueller; "Pardon my french, but Joohyun is so uptight that if you stuck a lump of coal up her , in two weeks you'd have a diamond."

On the other hand, there's Im Yoona who seems to coast through life without even thinking about it. Every day is a mystery for the girl and she's more than okay with that. It wasn't that she didn't care about self discipline, on the contrary she believed it to be extremely important in order to live life happily, but only to an extent. She valued a truly free spirit over strict rules and regulations over oneself.

To once again quote Mr. Bueller; "A person should not believe in an -ism, they should believe in themselves." 

Well just like all people, the rule of moderation still applies. Too much of a good thing is a bad thing, too much of a bad thing is a really bad thing, and the right amount of good and bad can bring someone a truly substantial life. 

All in all, both girls are way past due for something a little different...