We don't realize how much time we spend on autopilot until something changes and catches us by surprise. One fine morning, thirty miles into a forty mile commute, I came upon the two mile stretch of gravel road that allowed me to bypass the heavily-trafficked highway into town. As usual, I had my light on its lowest setting since there wasn't any traffic and I was on a first name basis with the potholes. Unbeknownst to me, the county road crew had shown up the previous afternoon and put down about a foot of fresh gravel on what had been perfect, for me, hard pack.
My wheels were immediately buried halfway to the axles as my speed dropped from about 20 mph to zero. At least they used nice, rounded pea gravel. It was like landing on styrofoam.