Yesterday, I woke up with a familiar sensation, or what, for me, is a familiar sensation: a tingle in my upper lip. A slight, hair tickle itch. Fizzy, like I’ve rubbed my mouth with the skin of a habanero pepper. I went to the bathroom and turned on the light, unconcerned about burning my eyes with the sharp, sudden brightness. In the mirror, I saw the faint irritation lining a section of my lip about a quarter-inch long, barely noticeable. From experience, I knew it would erupt in the next few hours. A cold sore.