Lessons

Lesson the first: Heavy glass mugs do not fly.
Lesson the second: A heavy glass mug released over the oven will fall between the oven and the wall as if falling down a well. Makes a similar plunk.
Lesson the third: It is a bad idea to kneel on top of a gas stove/oven. Thus it is necessary to straddle the stove with one knee on each adjoining counter, being careful not to burn one's tender areas with the hot metal above the pilot light.
Lesson the fourth: A swiffer wrapped in duct tape does not provide sufficient stickiness to lift a heavy glass mug from its well. Duct tape has only enough stick to lift small things, like spice jars, spoons, or pieces of twine.
Lesson the fifth: Mugs have handles. If inserted properly, twine can be thread through a mug handle using a swiffer and much patience. See lesson #4.
Lesson the sixth: A loop of twine can lift heavy unbroken glass mugs out from behind an oven easily. Even with a swiffer in one hand and a flashlight in one's teeth.
Lesson the last: No mug can outsmart Elizabeth. Boys love her. Dishes fear her.

Here endeth the lesson.