If the show eventually answers this question, just let me know, but don't tell me the answer. I don't want to be spoiled. So, with that in mind...
Why did Healer confess to Yeong Shin as his alias, Bong Soo? He did that KNOWING that she had romantic feelings for his secret identity "Healer". Not only that, but he knows that he himself has romantic feelings for her. But, from his confession, it seems that he would prefer to be accepted by her as Bong Soo, for some reason. But I can't even begin to fathom why that might be. Does the show eventually address this?
For the record, that confession scene.... really the sweetest thing I've seen in a drama in a while.
"Are you confessing right now?" (A look of genuine disbelief mixed with concern. Min Young's eyes are so sincere here)
"Mm" (nodding his head, cool as can be)
"Sincerely?" (her concern very subtly switching inward, almost suspicious but curious about why this is suddenly happening)
^ I almost fell off my couch due to 'feelz'. I LOVE that one little extra word they wrote in: "Sincerely?" She's taken aback, but her focus is on really understanding her friend's feelings while trying to avoid misunderstanding. Although I may not understand the Why of this scene, I really really like that the confession happened so unexpectedly and in an unexpected way. It was very romantic and touching.