Pay attention:
Right now, notice what you haven't been noticing.
While still looking at the screen, take a deep inhale. What do you smell?
While still looking at the screen, listen. Listen to the multitudes of noises around you.
While still looking at the screen, feel. While still looking at the screen, notice your thoughts.
Isn't it odd how much was going on around (and within) you that you hadn't even noticed?
How much happens around you each second of each day that escapes your attention? What is "attention" anyway? Does this missed information even matter?
Answer to all: More than you realize.