Quote:Huh? I see 3 dimensions.

 

Unless you are super human, you don't really "see" 3 dimensions.  If you really saw 3 dimensions you could see in front of everything and behind everything all at once.  But just like a camera lens, we take 3 dimensional space and project it to a 2 dimensional plane.  Then we take that information to determine depth.  This is why we have two eyes (that detect two separate 2 dimensional images) and a brain.  This is why it's possible for someone who loses sight in one eye to lose his depth perception.  

 

A creature that fully saw 3 dimensions might believe he was moving within 4 dimensional space or higher.  Just like in the movie Interstellar, at one point the main character is floating around in what I believe was 5 dimensional space.  But, even so, it's still projected onto a 2 dimensional screen, and we are seeing 2 dimensions all the same.        

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