When you walk around, your vision system is processing a whole bunch of signals in milliseconds and judging that a visual object is a wall, or an imminent cliff, or a car heading towards you. This might be disturbing to a lot of people, but some of those guesses are errors.
Usama FayyadSometimes guessing is the best you can do. In the real world, we guess all the time and it serves us well.
Usama Fayyad