Knowing what to expect from a situation gives us comfort. It allows us a sense of predictability in an unpredictable world. We build up habits and rituals as a way of controlling our environment.
There’s a strong biological basis for this behavior. Deep in our primitive brain, a dense bundle of nerves called the basal ganglia spends its time wiring automatic responses. It helps create neural pathways that reinforce specific actions and behaviors given certain inputs.
Change is difficult for us partially because it runs in opposition to these established pathways. When circumstances change, these pathways no longer function as designed, forcing the brain into unknown territory. Most people experience discomfort when their established patterns break down, and until new habits are formed, they’ll remain disquieted by the changes they’re facing.