Deep within the cockles of a motorcyclist’s heart exists a mysterious vein, a vein with little known evolutionary function but a vein that plays a critical role in the development of a motorcycling Homo sapien. This vein, the dirt vein (from the Latin vena dirticus), is actually a small, glandular recording device that instantaneously increases the human heart rate upon sight, sound, or smell of a dirt bike. The growth of the dirt vein begins in early childhood, usually just after learning to ride a bicycle. It quickly doubles in size as the bicycling homo sapien transitions from sidewalk to dirt, in most cases a few months after the training wheels come off. The dirt vein reaches full maturity at the exact moment when the off-road bicycling Homo sapien encounters a motocross bike for the very first time. The knobby tires, the symphony of combustion, the aroma of exhaust; all stimuli cataloged in perfectly preserved format for the duration of its being. A truly remarkable organism, the fully matured dirt vein replays this encounter routinely during the lifespan of the motorcycling Homo sapien, in some documented cases well over 600,000 times. Special thanks to Meatball and the Hell on Wheels MC for hosting another ridiculously fun event. Our dirt veins are throbbing.