At some point, you have to make a decision. Boundaries don't keep other people out. They fence you in. Life is messy. So, you can waste your lives drawing lines. Or you can live your life crossing them.
In life you will realize that there is a purpose for everyone you meet. Some will test you, some will use you, and some will teach you. But most important are the ones that bring out the best in you. Those are the ones worth keeping around. :) So true.