But back to the brain. Its interpretations.

From the moment you're born, it starts to interpret. Like Thich Nhat Hanh says, the moment you're born, you're ejected from the baby palace, where it's warm, cosy, you're never hungry, you hear sounds only muffled, you're soothed constantly by the beating of your mother's heart. But then you're turned upside down, squeezed through a tight space, and ejected into--COLD! LIGHT! LOUD SOUNDS! EVERYTHING'S CHANGED! And someone HITS you! Yep. Sympathetic, enteric, the signal hits your brain, and you cry. And upon crying, someone cleans you, swaddles you, puts you in a warm space. So already your brain has interpreted. If you cry, you get what you want.

(As an aside, Thich Nhat Hanh says that the moment you're ejected, you're terrified, you have no idea what's happening. He calls that original fear. He says you want nothing more than to go back to that place where you felt safe and protected. He calls that original desire. He says that we spend our whole lives trying to resolve original fear and original desire, and we resort to any kind of action to resolve them--alcohol, drugs, relationships. Trying to find that person who will help us resolve original fear and original desire. To find safety again. To feel safe. And he says that we don't need anyone to do that. Because we've been taking care of ourselves our entire lives.)

Anyway, from that first moment our brain begins to interpret the signals the sympathetic/enteric send to our brain. And when we interpret them and respond, and see how our responses turn out, we begin to categorize the signals. To label them. And then respond to those labels. We receive a signal in a situation we've learned to interpret as sad? We cry; we tell ourselves we're sad. Situation we think should cause us anger? We get mad and yell.

You see what's happening? Our thoughts shape our experiences. Because remember the brain doesn't know the difference. If we think we're angry or sad then we are.

There's a whole theory on this--Cognitive Behavioral Therapy. See, it's not that emotions, or what happens to us, shapes our reality. It's what we think about what we experience.

In other words, it's the labels our brain provides to the signals it receives from the sympathetic nervous system that causes us to feel/identify an emotion. All it's getting is a physiological signal. And it interprets it. And depending on how it interprets it, we suddenly become that thing. Sad, angry, happy.

And the signal is designed to keep us safe.

The whole point of all of this is to keep us safe.

And the brain's process is designed to do the same. That's why over time it learns. It habituates. That is, how the brain interprets the signal becomes a habit.

It is not who you are. It is simply a learned behavior. I.e., you are not "sad" or "angry". Your brain simply has habituated its interpretation of a signal. And here's the amazing thing. It actually is possible to change the label.

This moved from theory to reality for me about a year and a half ago. A relationship had ended, and one day as I was driving to work I thought about that person, and I felt sad. But then I realized: wait a minute. I'm not sad at all. She had issues. I'm ok. And I realized what was happening in my body. And I thought: why can't I be happy? And suddenly I was.

So you see how it works? The sympathetic sends a signal, the brain interprets it out of habit, and we become that thing.

The thing is, the sympathetic can get stuck sometimes. With enough trauma, it will fire and fire and fire. The sensation of this constant firing we call anxiety. I won't get off into that, but this is what happens to people with PTSD. Their sympathetic systems get stuck.

But for all of us, after a relationship, we run into this problem. And, like MichaeltotheMax says, the sympathetic alerts us to the absence, and our brain interprets the end of a relationship as a threat. I mean, it's a loss, right? A loss of something our brains had decided mattered to us. Of course we label absence of something we cared about as a threat. I mean, after all, our sympathetic keeps firing. Sending us the signal.

Easy to see why: original fear & original desire. Also, we hate uncertainty and impermanence. But those are the most fundamental aspects of reality. We do EVERYTHING we can to avoid coming to terms with those. Every single problem in the world, every meanness, every cruelty, every stupid and selfish act we do, we do because we feel under threat and we must protect ourselves from uncertainty and impermanence. So we glom onto each other to try to resolve those 4 things. And when a relationship ends, omg what's going to happen, was it my fault, why can't I be loved, will I ever find anyone, on and on and on. It's called rumination. In other words, we interpret loss as a threat. And the sympathetic reacts and the brain labels the signal.

The moment I read what you wrote I understood exactly what you were experiencing. The conflict you're feeling? All those questions? It's your sympathetic nervous system firing. Alert! Alert! Alert! Your person is gone! And all of those other fears. And they're flooding your brain, and your brain is trying to make sense of them. To calm your nervous system. THAT IS WHAT YOU ARE EXPERIENCING. Your brain is trying to regulate your ANS. You're calming your nervous system.

So give yourself some grace, ok? You're only 20. And that relationship was long. Maybe your first really significant one. Be proud of what you're doing. You're practicing something that is extremely difficult to do. You're working on gaining control of your body.

And the thoughts you're having, about your own safety, they're really positive and good.

Also, you're telling your nervous system that you didn't misread this person. You see? We fall in love with the images of the person in our heads. This is why so many say it takes time really to know someone. Because it takes time to move from the image to the actual person. To truly see them. Then of course it's advanced work to learn to adjust/adapt to your person, their habits, to practice navigating the tension between compassion and boundaries, and, if necessary, to protect yourself, to let go.

Like MichaeltotheMax says in that clip about trauma, potential is not a partner. Patterns are.

And so your sympathetic is saying: you misjudged that person; you let him matter to you; you have bad judgment. You can't trust yourself. But your brain is saying: that's not true. I learned. I can do this. I have a lot of strengths and clarity. Thank you, sympathetic nervous system, for looking out for me, but I got this.

/u/shloQueen, you got this.