You're not as alert as you think you are, even when you're trying to be. Our focus on certain things will leave gaps in other areas of our attention.
I had an idea as to what was going to happen in the first video, but had never actually watched it. It's funny, because when I watched the video again I noticed that my count was wrong. Does that mean that my situational awareness dropped?
Our awareness is dependent on two factors: The average field of direct vision being roughly the size of a quarter held out at arms length. The second one being that it is easy to stop logical thought, as you can see here http://www.pddnet.com/column-krystal...e-cake-022610/
It doesn't necessarily mean we're daydreaming, but more of an admission that we aren't omniscient. Is it possible to be in a
state of heightened awareness? I guess it is, but it seems to me that general awareness and specific focus are opposite ends of the spectrum.