Why do people hate themselves so much they sublimate with food, and eventually come to the point where they put everything the have into changing themselves, and then cheat on their diets?

I wonder why so many seem to think "relationship" is some sort of utopian magical kingdom with high walls and a cornucopia focused on immediate gratification of anything and everything without any negative long term consequences, that intrinsically protects someone from people being people.

Why do so many people think that saying, believing, and/or feeling something at one point in time will dictate and create a new perpetual reality?