human perception

0. This is analogous to the way humans and animals perceive the world: after observ- ing a scene for a few seconds, a human can remember which abstract objects were present in it (bicycle, tree) but can’t remember the specific appearance of these objects. In fact, if you tried to draw a generic bicycle from memory, chances are you couldn’t get it even remotely right, even though you’ve seen thousands of bicycles in your lifetime (see, for example, figure 5.28). Try it right now: this effect is absolutely real. You brain has learned to completely abstract its visual input—to transform it into high-level visual concepts while filtering out irrelevant visual details—making it tre- mendously difficult to remember how things around you look.
   
   From "Deep Learning with Python"