To translate this video into a real world example, it's a lot like if you guys are in a club and are so focused on a girl that you fancy...just WAITING for her to give you a sign of interest...while all around her there are 21 other girls who are jockin' the SHIT outta you.
I'll try to expand on this one - I knew I had to notice sudden changes and things that usually slip my mind in this video. In spite of knowing this, I only noticed one change (That what the butler was holding changed. How I could have missed the bear being exchanged for a suit of armor is eye opening).
So in spite of all the things I've read here and the knowledge I have, I'd still only notice one girl out of the 21 jocking me. Such a long way to go.