"She doesn't feel safe knowing she can push you around. She wants to know that you will stand up to her. That is how she will feel secure in the relationship. But, here's the catch. She has to test to see if she can trust you. The first time you set a boundary with her she may react intensely. She will push against it. She will tell you that you are wrong for setting that boundary. She will do her best to find out if your boundary is for real."

While originally intended for the husband-wife relationship, this is pretty easily adaptable to show exactly why we need to pass shit tests.

I'm quite glad I'm finally taking the time to read this. Recommended reading for all. Next on my list is the Book of Look, then Plato's Republic.