This is pretty off-topic, but interesting nonetheless. Have you seen this video yet? If not, take a few seconds to check it out--it's fairly mind-blowing.
Want to know why we are so selective in our vision? Here's the science behind what's called change blindness.
Makes me wonder if there isn't a mental version of change blindness as well, where we only grasp familiar concepts, or those we expect to see, or those we are looking for. How much gets caught in our mental filter and never makes it to our conscious minds?
Maybe this isn't so off-topic after all: Not only could a demonstration along the lines of that ad serve as a great waker-upper for a keynote, but the concept is something planners, and presenters, should think about when designing a session or a meeting. As a cost-cutting measure, what will never register with your audience and so can be omitted painlessly from your budget? From an adult-learning perspective, how is this perceptual gap helping or hindering your efforts to educate your participants?
I'm just finding it really interesting to think about this morning.