The Cup Before You
Imagine a cup front of you. It's a nice cup, 20 oz container with a catchy logo on on it. As you come close to it, you notice it is filled with dirt.
As hard as you try, you just can not seem to empty the cup. Perhaps it is bolted down.
Now as you ponder this cup, a stream of muddy water begins to flow from above and down into the cup, filling it up to the brim. Now it's overflowing.
You hear the question behind you, "How do you clean the cup?".