Acceptance is a key concept in self-esteem and relaxation. Acceptance doesn’t mean that you have to agree with everything or that you have to be ok with wrongdoings.
Acceptance means living in reality. It means seeing things as they are. Not better, not worse. It means being honest, with yourself and with what the world is.
Acceptance is a necessary step towards change, towards improvement, and towards healthy action.
The first step toward change is awareness. The second step is acceptance. — Nathaniel Branden
And this is what the mindset of Killing the SHOULDs is achieving. Instead of unnecessarily fighting against what the world should be, how people should behave and what you should be doing, you instead accept that the world is what it is, people are who they are, and you are what you are—your body is what it is, your thoughts, your feelings, all are just are.
It doesn’t mean that you cannot do anything about it though.
You can build the world to be a better place, you can let people know that some of their behaviors are not ok, and you can improve what you believe are your weaknesses.
But you are not fighting anymore with the world, and more importantly, with yourself.
And your world becomes a better place.