What do 당신 think Effy's 모토 means??

I think it means that each individual has his/her own ideas of how they should live their own life, even if at times it means being selfish, because at the end of the day, everybody is working for his/her own benefits.

that people will make decisions based on feelings momentary and not and that is how we live our lives. (heart rate connected to high emotions 심장 goes 'boom boom' when going fast and hard)