Before I forget Dave...nice car you got there. I have recently become quite partial to early cars with green paint.
My common answer is that: Any "good" pool player can make 1, 2, and 3 cushion shots all day. Billiard play requires 4 and 5 cushion shot knowledge to be in the top shelf of your tool box. Those tools must be handy while you also "corner play" the other two balls.
Three cushion billiard play (there are other more difficult versions as well) is all about herding the play ball (the white ball without the little red dot) and the point ball (the red one) into a corner. Once you have done this...you can shoot away for 3,4, and 5 cushion shots and back to both the play, and point ball, for a game point all day long. The ugly guy you are attempting to remove money from can do the same though.
This is where the "must win by two points" rule enters. And the night becomes a new clear day while you were busy playing with insanity.
Which brings me to my honest answer. "Cause it is stoopid and so am I." Shawn.