I have to say, I was skeptical about the drama, I don't know why my self. Probably because there are so many dramas with similar plots, you know the good old changing in bodies between two characters. I only started to watch because my friend recomanded it. After I've watched the 1st episode I couldnt wait to watch the rest & I cant wait to see the ending because I have NO idea how it's going to end. If I were to pick a drama by the title, this drama wouldn't be my first choice. I think, BIG is not something that attracts people. -The cast is really good. You can really feel with the characters. Gong Yoo is doing an awsome job of portrating a guy with mental age of 18 that is stuck in a body of a 30 something years old. At first I didn't like that he's the lead male, but after I watched a few more episodes I couldn't ask for a better one. His acting is really hilarious and matches the one of 18 year old. It's my first time watching him in a drama and I'll deff watch more dramas with him. -Shin Won Ho. I really fell in love with him after episode one. He really caugh my attention with his acting and I was really disappointed when I realized I wont be seeing him in the drama more. He was really convincing & gave of that cool feeling. Even tho he kinda acts tough on the outside, from his acting, we can see that Kang Kyung Joon is actually scared on the inside. I really want to see him in more dramas as a lead actor. -Min Jung is playing a teacher that is, in my opinion, really in love with Yoon Jae. SHe's really dense because, she's blinded by her love that doesnt realize that Seo Yoon wasn't faithful. We can clearly see that he has something goin on with that doctor, SeYoung. In my opinion, when he went to see her in ep 1, he was going to tell her that he was leaving her. Min Jung is, I think really suited for the character, and even though many wanted Suzy to be the main, I think Min Jung is better for this part. -Suzy, well, she's I think Kyung Joon's girlfriend back in America. I don't quite get what happened between them so he doesn't want to see her. I think Suzy's cahracter is really funny in the drama and suits her really well. It's annoying at times but gives a refreshing string to the drama. Somewhat, remindes me of Go Hye Mi in Dream High. -The rest of the cast is really good too. I like Gil Da Ra's brother, he's really funny, and I liked the way he flirted with MaRi:P The parents, I like them too, but I think in every drama that I've watched so far, the mother is always goofy and funny while the dad is more serious :P Music is okay, ballads mostly, it's enjoying. It's not something I would listen to everyday, but I really liked the OSTs. Esp the BEAST one. It matches the story. Re-watch value. Well, I don't usually re-watch dramas no matter how good they are. But yeah, it's something that I would watch after sometime. Well, maybe not the whole episodes but the parts that really left impressions on me. It gives a good laugh in every episode, no exeptions. Over all, I give it a 9. Everything is put together nicely. It very enterteining and something that you should DEFFINAELY watch no matter what age you are.