Last week, I happened to be chatting with a colleague about perception. The conversation's topics ranged from how people differ, to how no two people can view the world through the same set of experiences. We decided that even our ideas on something as fundamental as the campus location cannot match. We are affected by the location of our residences and paths to BCIT. My own conclusion is that people who maintain there is 'universal truth' are naive.
Futhermore, those who maintain there are grey areas in life should note that our ability to see them can be a source of consternation too.
Squares A and B are exactly the same shade of grey.

For proof and an explanation, visit
Checkershadow Illusion.