If you have ever been in a relationship with a narcissist, you know that agonizing feeling of constant oscillation. In one moment, they are vulnerable, collapsing into depression and pleading: “Don’t leave me, you’re the best thing that ever happened to me. I’m so happy.” In the very next moment, they turn cold and dismissive: “I don’t even need you. You’re worthless.” I remember one afternoon, not even six months into our relationship, finding her at home in tears, terrified that I might leave.