Well, I can imagine two reasons why you might feel like you are going very fast while spinning in a circle, even if you are in reality spinning very slowly. The first reason is visual (with your eyes). If you stand in the middle of a room and spin around once, your eyes have traveled around the whole room in a very short time. If you walked around the perimeter (outside border) of the room looking straight ahead to travel the whole distance, it would take a much longer time. The second reason is balance. Believe it or not, your inner ear is in charge of how your body balances. There is a fluid inside of your inner ear, and spinning around disrupts the fluid and makes you feel off balance. This is why you get dizzy and maybe light-headed or blurry vision when you spin many times, and being off balance can also make you feel like you are going faster than you actually are.