Mike was watching TV and all of a sudden he leaps to his feet and says, "That's Simon", pointing at someone who was at the screen.
Then his brother Mark comes in, looks at his brother, then looks back at the TV and says, "So it is."
How do they know Simon if they hadn't seen him before, no pictures, nothing?
You have a sock drawer.
It has 4 black socks, 8 brown socks, 2 white socks and 8 tan socks.
You need to pull out a matching pair of socks in the dark.
There is no light and you couldn't see the socks.
How many socks you should pull out in the dark to get one matching pair of socks?
Five. You have only four different colors of socks. If you pick 5, you can surely get one pair of matching socks.