I think people underestimate being the primary parent. The one to do everything important, appointments, daily routine, keeping a roof over their head and food in their mouths.. etc. if i want to go out every weekend. I will. If i want to vacay and date. I will. Babysitting the LEAST anyone can do.
You can tell a lot about a person by what they do after hurting you. Some apologize. Some reflect. Some change. And some will rewrite the entire story in their head just to avoid feeling guilty. Accountability is rare because protecting the ego is easier than becoming better.