You know the moving sidewalks at airports? Imagine being behind somebody just standing on the sidewalk (and filling up the full width so nobody can pass) when you're really in a hurry somewhere. This joke is somewhat related to the frustration in that situation.
Also: Now I can't stop imagining standing behind you, watching you move the mouse pointer slooooowly over the screen to press the COPY icon. All the while my mind is screaming "CONTROL+C! CONTROL+C!!!"