I also believe we can re-train our brains.
My understanding of it is that when we're in those highly emotional situations, we literally create new neuro pathways in our brains. So, that when we are again confronted with the fear or whatever intense emotional response we have, we dig that neuro pathway a bit deeper until it is one of the only paths the brain is taking. However, if we can step back, observe what we're doing, become conscious of it, we can choose a different response thereby creating yet another new neuro pathway in the brain which might offer peace or calm, instead of worry and fear.
I've done this with being aware/mindful, meditation, getting out the door to hike if I'm taken over with negative emotions (statistics show that even a mere 11 minute walk has the potential to shift our brains). Changing my diet because sugar/dairy and other food items create inflammation which impacts the gut which then impacts the brain.
We can shift our negative responses to life. However, it takes a commitment, it doesn't just happen. We have to choose to make the changes, to be aware of how we fall into these traps and pull our own selves out. We have to be willing to change and do the work change demands.
As the saying goes, "Pain is inevitable, suffering is optional." We have more power than many of us believe we do. We have the power to shift our beliefs, our responses, our perceptions.
I was reading an article which stated that our beliefs are simply "opinions" based on our history. It's easy to think our beliefs are THE TRUTH....which then keeps us stuck defending that truth.....if we can step back from all of that relentless mind chatter long enough to create an open space, it's a lot easier to then be available to new data. Meditation is probably the biggest support in opening that space because it stops the mind chatter long enough for new, healthier thoughts to emerge.
Like Tanya and SWOT have so successfully shown, we can change, we can have lives which reflect our peacefulness, our joy, our sense of authenticity and pleasure.....however, we have to be willing to let go of what isn't working and what is making us suffer and open to a new awareness. Not always easy, but absolutely doable.