We can get so easily sucked dry by energy vampires or give up too much of our personal power when our boundaries aren’t firm. These energetic barriers between us and everyone else are our own personal magic circle. Understanding them and the consequences for when they are violated are important skills to develop as a witch.  Since you are engaged in energy work, may be an empath or a psychic, and probably are a healer of some sort, it’s important to have firm barriers so that you don’t get sucked into another’s harmful energy. Think of your boundaries as the forces you call to protect yourself just like when we call the elements to help us casting the circle.