To make sense of the world, the brain determines which sensations are the most important, focusing resources on them and throwing away the rest. One way to see that is through the phenomenon of change blindness.
It’s something completely normal and is caused by maxing out your attentional capacity. All of the information enters your visual system in the same way and is processed by the retina the same way.
However, the inputs encounter a tight bottleneck that causes you to miss the seemingly obvious, unless you know where to focus beforehand. Change blindness is why we tend not to notice continuity errors in films and why many traffic accidents tend to happen.