Relative Motion

So I work and this restaurant where we do this thing and cook food and then we give it to people and they eat it and enjoy it and stuff. So we have this one oven that is basically just a conveyor belt with a giant heater blasting down warmth to cook food. And I know it's blasting because the sound is almost deafening. And this thing is basically running constantly, to the point where you just get used to it and forget that it's on, like if you always hear traffic outside of your window, but only notice it when there aren't any cars. But anyway, we were having a slow day and I was hanging out in the kitchen, trying to get everything wrapped up so that when we did the final clean up that night, it would go quickly. At one point I was walking across the kitchen and I looked at the conveyor belt thingy to see if it was on. It appeared to me that the belt wasn't moving, so I assumed it was not. But then, as I stopped on the other side, I realized that I was wrong. The machine had indeed been running, but since I was walking at the same pace, it appeared to me as though it was not. this is a prime example of  relative motion affecting real life.