Mental Manipulation: The Hole in the Folded Paper

You have a square sheet of colored paper. You fold it in half from left to right to make a rectangle, then fold that rectangle in half again from top to bottom to make a smaller square. In this folded state, you punch a single hole right through the dead center of the small square.

Without using your hands, unfold the paper in your mind's eye alone. When it is completely unfolded, how many holes are in the paper in total?