Cognition, I guess it is better to say, is not so much flawed as it is limited, and in many ways that is a flaw.
1.  Our senses can only concentrate on so much so that a particular perception, although seemingly complete, can be very incomplete and can give us a distorted view that surprise us to be otherwise.
2.  Our senses have only existed for a short time.
3.  Our senses contradict each other.  Perfect senses would not, as I demonstrated with the 3d movie example.
4.  Our perception cannot collect all information at once.  It  is limited by direction and in scope.
5.  Our thought can contradict our perception
6.  Our perception's ability can change.
There is no right or wrong standard I'm implying here, other than the one relative to one's own perception.  I think 3 is the best example of this, simply for the fact that it distinguishes between an outside standard and an inside standard by stating that our own senses conflict with each other.  Logically, I believe nothing perfect can contradict itself: it must be completely congruent.  But that is another debate.

9.  There is a plane of existence I assume carries on its own existence for simplicity's sake.

**There's some sort of famous rule of logic that says out of two equally explanatory answers, the simplest one is normally correct.