If Yena hadn't been so selfish, she would still be happy. If she wasn't so selfish, she wouldn't be scared and help Myeong with her career. If she wasn't so selfish, she wouldn't be a homewrecker and still be friends with Myeong and Hyeongjae. If she wasn't so selfish, she wouldn't have ruined a relationship. If she wasn't so selfish, at least a tiny bit more selfless, she would have the ability to smile sober.
If Yena hadn't been so selfish, she would still be happy. If she wasn't so selfish, she wouldn't be scared and help Myeong with her career. If she wasn't so selfish, she wouldn't be a homewrecker and still be friends with Myeong and Hyeongjae. If she wasn't so selfish, she wouldn't have ruined a relationship. If she wasn't so selfish, at least a tiny bit more selfless, she would have the ability to smile sober.