I used to think that the crawling sensation on my back was a symptom. It began as an occasional twinge and grew into an ache, passing from the base of my neck down to my lower back in waves. Perhaps it was some manifestation of anxiety or dread; it certainly occurred alongside those things. The unease in my gut. My clenched jaw. The tightness in my chest.
Those sensations hit me in turn as I suffered through my first Medical Neuroscience exam in graduate school. Dread overtook me when I reached the sixth question and realized I was woefully underprepared. I already had been subjected to multiple anatomy courses in undergrad, not to mention that my earlier courses as a graduate student had already covered much of basic neuroanatomy. Yet, I had not prepared for the specificity or style of questions on this exam and my skin crawled with anxiety. By the time I reached the section on brain development, my mind had gone blank. Sweat gathered on my brow as I contemplated the possibility that perhaps my own brain had failed to develop at all.