You’ve probably heard it before: “Just leave.” “You deserve better.” “If you had more self-respect, you’d walk away.”
When someone stays in a toxic relationship, we assume they’re weak. Or desperate. Or that they don’t value themselves enough to demand better treatment. We see them going back after another fight, another betrayal, another promise to change, and we think: What’s wrong with them?
Here’s what we miss: the good parts were real.
That’s what makes toxic relationships so insidious. They’re not 100% terrible. If they were, leaving would be simple.
Instead, they’re this maddening mix of genuine connection and genuine harm. The person who makes you feel understood like no one else also makes you question your reality. The one who knows exactly how to comfort you also knows exactly how to wound you.
And your brain? It can’t let go of something it’s still hoping will return.
Your brain is wired for the familiar, not the healthy
I used to think leaving toxic situations was about willpower. Make the decision, stick to it, move forward. But watching a friend cycle through the same destructive pattern with her partner taught me something different.
She’d leave. She’d come back. She’d leave again. Each time, she’d say the same thing: “But when it’s good, it’s so good.”
Stephanie Moulton Sarkis, Ph.D., author of ‘Gaslighting: Recognize Manipulative and Emotionally Abusive People—and Break Free,’ explains why this happens:
“The brain tends to stick with what is familiar and predictable. You have been through the loop of lovebombing and abusive behavior, usually several times during this relationship. Peace and stability, as you find in a healthy relationship, can feel unknown and uncomfortable.”
Think about that for a second. Your brain literally finds chaos more comfortable than calm because it’s what you know.
It’s like being addicted to a rollercoaster. The drops are terrifying, but the highs? They’re intoxicating. And after enough rides, standing on solid ground feels wrong. Too still. Too quiet. Like something’s missing.
This isn’t weakness. It’s neurological conditioning.
The good times rewrite the bad
Have you noticed how memory works in relationships? The fights fade. The cruelty blurs. But that one perfect Sunday morning when they made you coffee and you talked for hours about everything and nothing? That stays crystal clear.
Our brains are terrible historians. They edit the past based on what we want to believe about the present. And in toxic relationships, this selective memory becomes a survival mechanism.
Seth J. Gillihan, Ph.D., a licensed psychologist specializing in mindful cognitive behavioral therapy, captures this perfectly: “The good times can make it seem like the bad were just a phase—or worse, something one or both partners were making too big a deal out of.”
Every good moment becomes proof that you’re overreacting. That you’re being too sensitive. That if you just tried harder, were more understanding, gave them more time, you could have the good parts without the bad.
You’re not just fighting to leave a person. You’re fighting your own brain’s desperate attempt to preserve what felt like love.
Hope is the cruelest anchor
The most painful part? You’re grieving someone who’s still alive. Someone who could, theoretically, become the person you fell in love with again. Tomorrow. Next week. If they get that promotion. If they stop drinking. If they go to therapy. If, if, if.
You can’t properly mourn something that might resurrect itself.
I’ve watched this play out in different contexts. A friend who couldn’t leave a job where her boss alternated between praising her brilliance and questioning her competence. Another who kept returning to a friend group that made her feel like she belonged one day and invisible the next.
The pattern is always the same: just enough good to keep you hoping.
It’s like slot machines. Behavioral scientists know that intermittent reinforcement—random, unpredictable rewards—creates the strongest psychological attachment. You never know when the good version will show up, so you keep pulling the lever. Keep showing up. Keep hoping this time will be different.
The real cost of staying
Here’s what no one talks about: staying changes you at a cellular level.
Your nervous system learns to live in fight-or-flight mode. You become an expert at reading micro-expressions, sensing mood shifts, managing someone else’s emotions. You get so good at anticipating danger that peace feels threatening.
I remember realizing I’d become a different person in certain relationships. Not the fun kind of different where you discover new parts of yourself. The kind where you lose parts you didn’t know were negotiable. Your opinions get quieter. Your needs get smaller. You optimize for avoiding conflict instead of seeking joy.
You tell yourself you’re being understanding. Flexible. Loving.
Really, you’re disappearing.
Why leaving feels like losing
When you finally leave, or try to leave, something unexpected happens. Instead of relief, you feel worse. Instead of freedom, you feel lost.
This isn’t proof you made the wrong choice. It’s withdrawal.
Your brain is literally going through chemical withdrawal from the highs and lows. From the intensity. From the hope. Healthy relationships, with their steady warmth and predictable kindness, feel like eating salad when you’re used to sugar rushes.
Plus, you’re not just leaving a person. You’re leaving a version of yourself. The one who could handle it. Who was special enough to be the exception. Who could love someone into becoming better.
Letting go means admitting that love isn’t enough. That you can’t fix someone. That all your effort, understanding, and patience couldn’t change the pattern.
That’s not failure. That’s physics. You can’t love someone into being different any more than you can love water into not being wet.
Final thoughts
If you’re in this cycle right now, know this: your brain is doing exactly what brains do. It’s trying to protect you by sticking with what’s familiar. It’s trying to make sense of confusion by focusing on the good. It’s trying to preserve attachment because attachment meant survival for our ancestors.
You’re not weak for struggling to leave. You’re not stupid for going back. You’re human, dealing with one of the most complex psychological experiences there is.
The good parts were real. That person who made you laugh, who understood that thing about you no one else did, who made you feel seen in a way you’d never experienced—that was real. You’re not crazy for missing it. You’re not pathetic for wanting it back.
But here’s what else is true: the bad parts were real too. And you deserve a reality where you don’t have to choose between being loved and being safe. Where you don’t have to shrink to fit. Where peace isn’t the exception but the rule.
Your brain will catch up eventually. It will learn that calm isn’t empty. That predictable isn’t boring. That being treated well consistently isn’t “too good to be true”—it’s just good.
Until then, be patient with yourself. You’re not just leaving a relationship. You’re rewiring years of neural pathways. You’re grieving both what was and what could have been. You’re learning to trust solid ground after living on a faultline.
That takes time. And courage. And probably more attempts than you’d like.
But you’re not doing it because you’re weak. You’re doing it because somewhere, beneath all that hope and hurt, you know you deserve more than good moments scattered between bad ones.
You deserve good that stays good.
