Someone’s boundaries aren’t meant to control you.

If someone builds a fence around their yard, it’s not built to figure out the boundaries of your yard so that they can tell you what to do and how to behave. The fence was built so that they can maintain control of what happens on their property, not yours. Personal boundaries do the same. If someone trespasses on to your personal boundaries in some way, you can take control of yourself and not allow yourself to be controlled anymore. That is the essence of self control.