A childhood belief about going shopping

When I was a kid, typical grocery stores in my town had slanted mirrors in places, like behind the produce bins. For a long time, I didn't realize that they were mirrors. I thought they were windows allowing a view into a different part of the store, a part that wasn't level but steeply slanted. It seemed almost a magical part of the store. Shoppers there seemed to effortlessly walk up the steep floor with no danger of sliding down. And they could leave their shopping carts in place without them rolling downhill. I figured that it was only a matter of time until my parents would have occasion to shop in that other strange and wonderful part of the store, and they would take me there with them. Eventually I was very disappointed to learn that no such thing would ever happen.