Very true. It's the predictive nature of the human brain. The fact that over the years, we learn what to expect to hear/see and the brain filters out false information. Very cool. It's kinda like the blind spot phenomenon. We all have a blind spot, but we never see it. If you hold a piece of white paper with a dot on it and position the dot in your blind spot, you "see" all white, even in your blind spot. Do the same with a green sheet of paper, you "see" green. Do the same with a piece of paper with stripes on it, you "see" stripes. Neat. The brain just draws in what it expects to be there, whether you know it to be true or not.