The brain is the only organ in the human body that was designed to learn. As a result, our life experiences sculpt the shape, size and function of the entire neural network; a phenomenon known as experience-dependent neuroplasticity. Interestingly, negative life events have a greater impact on shaping the brain than positive experiences. As a matter of survival, humans evolved with a negativity-bias. We are wired to pay attention to painful events, react to them quickly, remember them well, and become more sensitive to anything remotely similar to avoid future happenings. This is why traumatic events have such a lasting impact on people. Trauma can dramatically affect the size and function of key brain structures that we use to interpret the world. Understanding the neurology of trauma is imperative for professionals who work with people who were exposed to intense or repeated traumatic events.