It is just you.. No it has to do with the frame rate of the camera and the speed of the tires. An optical illusion. Cameras take a series of still pictures unlike you eye. And at the right speeds for the frame rate and the rotational speed of the tire it can appear to either stand still or even rotate backwards due to the stroboscope effect. That is the best I can explain it. Perhaps others can put a finer point on it.