Your brain is trying to do its job—to keep you safe. And in caveman times, that meant responding to danger that came and went. You run from a tiger, your heart rate increases, adrenaline kicks in, and suddenly you’re on red alert—WAH WAH WAH.
If you had a highly sensitive nervous system, that hypervigilance was useful. You were one of the lucky ones—you survived. You got out of the situation, and your body slowly returned to normal.