Interesting what goes through people's heads while riding. I find it best for me if I have no thoughts of that kind, or music or counting. Instead I notice the traffic, the feel of the wind, the sound of my tires on the road, the angle of the sun, my feelings of exertion or thirst, tired or strong legs, my speed and distance so far, the smell of fresh cut grass, a new coat of paint on a familiar barn, the need to get up out of the saddle for 30 seconds, and so on. I try just to let my mind be open to what's going on with the ride, and there seems to be plenty to keep me occupied.