The hardness of the road. The hardness of tarmac. We know in our heads it is unyielding, a solid, unmoveable object, a irresistible barrier that does not flinch under the impact of mere flesh and bone.
Yet nothing, not a thing, can mentally prepare us for the sheer shock of impact when we fall, unexpectedly from bike, or in my most recent case, longboard. The hardness of the road leaves us breathless, and quaking, as, prostrate, we reboot our bodies one digit, one limb, at a time, fearfully expecting the stabbing pain of a fracture, and even as our jangled brain becomes slowly aware that, yet again, we will live to ride another day, ride home even, a part of us is screaming "Wow*, that really hurts. And this tarmac is dreadfully* hard."
*other expressions are available.