> I have to strongly disagree with you on this, I can walk around in my (small) city in my mind in 3D without any problems. Anybody who's ever had a dream would

> I have to strongly disagree with you on this, I can walk around in my (small) city in my mind in 3D without any problems. Anybody who's ever had a dream would concur as well. It's absolutely not true that humans can't think in 3D. Well, some people reportedly can, but it’s rare. You say you can imagine walking around your small city, and infer that you have the city conceptualized as a 3D object, and can rotate it at will, in any direction. But how do we know that you simply have not memorized your admittedly small city? Can you imagine what going around the city upside down (i.e. like walking on your hands) would look like, with ease? It should be just a simple rotation, right?