Eh, what's that? People are bad at noticing stuff. In companies they don't notice the stuff that is blindingly obvious to outsiders (or people not as close to the situation).
What better way of demonstrating this than a little magic. Watch these two videos to see this in action.
Richard Wiseman - card color change
Penn and Teller - cups and balls (with clear cups!)
Now think of all those situations (professional and personal) where you missed changes - I know I have, lots! Here's an extract from Wired magazine which casts some light on this:
Attention, it turns out, is like a spotlight. When it's focused on something, we become oblivious to even obvious changes outside its narrow beam. What magicians do, essentially, is misdirect - pivot that spotlight toward the wrong place at the right time.
ZeroTouch IT Ltd