I was in my cage, in the outside curve of a 180 degree, decreasing radius off/on ramp at about midnight. A crotch-rocket was coming from the opposite direction, way too fast for the inside curve, on ramp. He jumped the concrete center divider and crossed diagonally in front of me, while the handlebars rapidly oscillated. I braked hard and he continued across. I estimate that I missed hitting him by 15 - 20 feet, which is much too close for comfort, in the dark, at a fast closing speed. I stopped but he continued on, embarrased, I'm sure, and probably with brown underwear and a few less years of longevity from extreme stress. I know my own pucker factor instantaneously maxed. We were both lucky.