Composer Yoon Sang recently stated his very reason why he gave IU the type melancholic song entitled "The Story That Only I Didn't Know About," and that was because of IU's perfect impression of melancholy.

In a recent airing of "Yoo Hee Yeol's Sketchbook," composer Yoon Sang  particpated as a guest and one of the said topics of conversation was  IU's "The Story That Only I Didn't Know About." Yoon Sang explained to the audience why he chose IU? He only encountered IU by watching on a variety show before she became popularly known as "nation's little sister," a title bestowed to her from her character in the hit show  "Good Day." He has a keen memory of that meeting and eventually he decided to compose the song, by stating "I composed 'The Story That Only I Didn't Know About' after seeing her melancholic face while being unable to mingle with the other guests."  Yoon Sang has previously composed songs for BoA ("The Show Must Go On"), Gain ("Irreversible," "Truth") and of course IU. 

The success of "Good Day," really made a bigger impact on IU's career opening doors to all possible projects and also composers gaining interest in her talents, like Yoon Sang. IU's songs are more on the preppy side but, the song that Yoon Sang composed is more of a ballad which really makes an impression to all listeners of the song. The extremely somber ballad that you might expect to hear from more veteran ballad singers like Lee Soo Young, got IU's innocent and young voice in it.  The song "The Story That Only I Didn't Know About" was very suited to IU's voice compared to what she used to sing.