How can you see black behind black?

Think about this, when you look at a black car which has black tires, black rims and a dark disc brake, how is it that your eye can differentiate the inapparent contrasts to visualize each component differently. Our eyes and brain can be so wonderful as to be able to differentiate black on black, yet when it comes to seeing obviously wrong things, our brain shuts off for those few moments and fail to register the act as obviously wrong. I think the question should not be what is wrong or right but rather what we do about it. I don't seem to understand why myself and many others choose consistently to ignore the wrongs before us and enjoy in those few moments of pleasure before we wake up to the idea of our stupidity and choose the better option. Maybe one day when I see the black car with the black tires, rims and disc brake, I will be able to draw it accurately instead of just "dollop-ping" black on white. Where's what?