Imagine you are making cookies. You gather and mix all the ingredients and then bake the cookies in the oven. At this point, it is impossible for you to remove the sugar, flour, or vanilla from the dough but keep the salt. The ingredients are combined in such a way that separate things have become something else in combination. This is my favorite way to think about memories formed during intense experiences. When we go through trauma, every ingredient of the experience combines in a way that makes it impossible to separate one from the other. So the brain combines the separate elements of a trauma into one memory package, engaging in some extremely helpful processes to keep us safe later. The elements might include things such as a smell, the time of day, the body's posture, close and faraway sounds (including music), lighting, who we're with, where we are, and what happened just before things got scary? Whatever is in the memory bundle associated with the trauma gets neurologically coded as deeply threatening to our safety. This packaging process is both helpful and unhelpful. It's helpful because if we encounter any of the trauma ingredients again, our brain can quickly activate a stress response mechanism to keep us safe. It's unhelpful because the mere presence of a trauma ingredient doesn't mean the trauma is happening again. In other words, even though you are in a similar situation, smell the same smell, or hear the same song, you are not necessarily repeating the trauma. Instead, you're experiencing a trigger- your nervous system is remembering something in the past based on something in the present. …The example I gave earlier about memory cookies, where all the sensory components get mixed together, applies to positive experiences as well as trauma triggers. Sensory elements can be combined to form memory cookies that help us know we are safe, cared for, and loved. So if you are alone and it is hard to access your truest self, imagine that a loving friend, your therapist, or anyone else who makes you feel safe is talking to you or sitting next to you. The memories and emotions you associate with loving people, or even by thinking of them, can help you access that feeling of love, which you can then use to help yourself feel safe.
Hillary L. McBride, PhD, The Wisdom Of Your Body